111144031-centac

CENTAC

CMC Technical Reference Manual

INGERSOLL-RAND

AIR COMPRESSORS

CMC TECHNICAL REFERENCE MANUAL

1X36003 Version 2.52 1996-1999 Ingersoll-Rand CompanyDate of Issue: 18-Oct-1999

Copyright Notice

Copyright 1996-1999 Ingersoll-Rand Company

THIS MANUAL IS SOLD "AS IS" AND WITHOUT ANY EXPRESSED OR IMPLIEDWARRANTIES WHATSOEVER.

Printing Date: 18 October, 1999

Ingersoll-Rand air compressors are not designed, intended, or approved for breathing airapplications. Ingersoll-Rand does not approve specialized equipment for breathing airapplications and assumes no responsibility or liability for compressors used for breathing airservice.



Table of ContentsWhat’s New In This Manual_____________________________________________ 1

References __________________________________________________________ 2

General - CMC Panel __________________________________________________ 3

Control Methodology __________________________________________________ 4

Performance Control ________________________________________________________4Unload _____________________________________________________________________________ 4Constant Pressure Control - Modulate ____________________________________________________ 4Energy Saving Control - Autodual ________________________________________________________ 5

How does Constant Pressure Modulation Work? _________________________________________ 6Measuring the Discharge Pressure __________________________________________________ 6Proportional Band ________________________________________________________________ 7Integral Time ____________________________________________________________________ 7Motor Current, MinLoad and MaxLoad________________________________________________ 8

Surge Control _____________________________________________________________10Control Methodology _________________________________________________________________ 10Surge Detection _____________________________________________________________________ 10

Insufficient Rise To Surge ___________________________________________________________ 10Changes in System Discharge Pressure _______________________________________________ 11Rapid System Demand Changes _____________________________________________________ 11Incorrect Instrumentation Output _____________________________________________________ 12How is Surge Detected? ____________________________________________________________ 12

Surge AbsorberTM___________________________________________________________________ 12Surge Indexing ______________________________________________________________________ 13

Oil System Control___________________________________________________ 14

Prelube Pump _____________________________________________________________14

Oil Heater_________________________________________________________________14

Protection and Monitoring_____________________________________________ 15

Analog Functions __________________________________________________________15Analog Inputs _______________________________________________________________________ 15Analog Outputs _____________________________________________________________________ 15

Digital Functions___________________________________________________________15Digital Inputs _______________________________________________________________________ 16Digital Outputs ______________________________________________________________________ 16

Compressor Operating Methodology ____________________________________ 17

Stopped __________________________________________________________________17Waiting ____________________________________________________________________________ 17Not Ready _________________________________________________________________________ 17Ready _____________________________________________________________________________ 17

Rotating __________________________________________________________________17Starting____________________________________________________________________________ 17Unloaded __________________________________________________________________________ 18


1X36003 Version 2.52 1996-1999 Ingersoll-Rand Company

Date of Issue: 18-Oct-1999

Loading____________________________________________________________________________ 18MinLoad, Loaded, Full Load and MaxLoad________________________________________________ 18Unloading __________________________________________________________________________ 18Coasting ___________________________________________________________________________ 18

Compressor Operating States _______________________________________________19

User Interface _______________________________________________________ 20

OUI (Operator User Interface) _______________________________________________20Command Keys _____________________________________________________________________ 21Enter Key - Display Operating Mode ____________________________________________________ 21Navigation Keys _____________________________________________________________________ 21Contrast Key _______________________________________________________________________ 22Graphic Display _____________________________________________________________________ 22

Folder and Page __________________________________________________________________ 22Status Bar _______________________________________________________________________ 22

Edit (Setpoint Changes) Mode _________________________________________________________ 23Navigation Mode_____________________________________________________________________ 23SYSTEM Folder_____________________________________________________________________ 25INFO Folder ________________________________________________________________________ 26SETTINGS Folder ___________________________________________________________________ 29

General Sequence of Operation _____________________________________________34

Indicator, Switch and Light Layout ____________________________________________35Lights _____________________________________________________________________________ 35Push Buttons _______________________________________________________________________ 35Switches___________________________________________________________________________ 35

CMC Tuning Procedures ______________________________________________ 35

Setting MaxLoad___________________________________________________________36

Setting MinLoad ___________________________________________________________36

Setting MinLoad Surge Index Increment_______________________________________37

Setting Surge Sensitivity____________________________________________________37

Tuning Stability____________________________________________________________38

Calibrating the Control Valves _______________________________________________39

Autodual Control Settings ___________________________________________________40Unload Point (Bypass Valve % Open) ___________________________________________________ 40Unload Delay Time (seconds)__________________________________________________________ 41Reload Percent _____________________________________________________________________ 41

Setting the Start Time ______________________________________________________42

Setting the CT Ratio________________________________________________________42

Inlet Unload Position _______________________________________________________42

Setting Set Point Ramp Rate_________________________________________________43

Alarm and Trip Settings _____________________________________________________43

Troubleshooting_____________________________________________________ 44



Troubleshooting Example ___________________________________________________45

Input/Output (I/O) System ___________________________________________________46Vibration Monitoring System (VMS)_____________________________________________________ 46

Checking Vibration Transmitter Power_______________________________________________ 47Checking Vibration Circuit ________________________________________________________ 47Check the Vibration Probe, and Cable_______________________________________________ 48Checking the Vibration Probe______________________________________________________ 48Check the BCM _________________________________________________________________ 49

Temperature Monitoring System (TMS) __________________________________________________ 50Checking for Power to the Temperature Transmitter ____________________________________ 51Checking for a Faulty RTD ________________________________________________________ 52Degrees Fahrenheit versus Ohms value chart for 100 OHM Platinum RTD __________________ 53Degrees Celsius versus Ohms value chart for 100 OHM Platinum RTD ____________________ 54Checking the RTD Transmitter _____________________________________________________ 55Checking proper operation of the BCM and wiring______________________________________ 56

Valve Control System (VCS)___________________________________________________________ 57Checking proper operation of the BCM and wiring______________________________________ 58Checking proper operation of the I/P and positioner ____________________________________ 59

Pressure Monitoring System (PMS)_____________________________________________________ 60Checking for Power to the Pressure Transmitter_______________________________________ 61Checking proper operation of the BCM and wiring______________________________________ 62Quick check of the PT ___________________________________________________________ 63Functional PT test_______________________________________________________________ 63

Digital Input System (DIS)_____________________________________________________________ 64Checking proper operation of the digital devices _______________________________________ 65

Control Power System (CPS) ________________________________________________66No AC power ___________________________________________________________________ 67No DC power ___________________________________________________________________ 68No digital input power ____________________________________________________________ 68No digital output power ___________________________________________________________ 68No analog input power____________________________________________________________ 68No analog output power __________________________________________________________ 68No OUI power __________________________________________________________________ 68No CPU power__________________________________________________________________ 69

Controller Problems ________________________________________________________70BCM Problems______________________________________________________________________ 71

BCM is not controlling____________________________________________________________ 71OUI Problems_______________________________________________________________________ 71

OUI is dim _____________________________________________________________________ 71OUI is black____________________________________________________________________ 71OUI displays “INGERSOLL-RAND Centrifugal Compressor Division”_______________________ 71

UCM Problems______________________________________________________________________ 71All UCM LED’s are not lit _________________________________________________________ 71

Options ____________________________________________________________ 72

Enclosures________________________________________________________________72NEMA 12 (IP 64) ____________________________________________________________________ 72Cooling Fan ________________________________________________________________________ 72NEMA 4 (IP 65) _____________________________________________________________________ 72NEMA 4X (IP 65) ____________________________________________________________________ 72Space Heater _______________________________________________________________________ 73




Vortex Tube Cooler __________________________________________________________________ 73Type Z Purge _______________________________________________________________________ 73Fused Control Power Disconnect _______________________________________________________ 73

Control Electrical Package __________________________________________________74

Stage Data Package ________________________________________________________74

Alarm Horn ________________________________________________________________74

Running Unloaded Shutdown Timer __________________________________________74

Water Solenoid Post Run Timer ______________________________________________74

Panel Mounted Wye-Delta Starter ____________________________________________74

N.O. Contact for Remote Indication of Common Alarm and Trip ___________________74

Power Regulating Constant Voltage Transformer_______________________________75

Automatic Starting__________________________________________________________75Remote Start and Remote Stop – Hardwired ______________________________________________ 75

Remote Start Digital Input ___________________________________________________________ 75Remote Stop Digital Input ___________________________________________________________ 75

Communications ____________________________________________________________________ 75Auto-Hot Start ______________________________________________________________________ 76Auto-Cold Start _____________________________________________________________________ 76

Remote 4-20 mA Pressure Setpoint ___________________________________________76

Steam and Gas Turbine Driven Compressors __________________________________76Performance Control _________________________________________________________________ 76

Motor Current, MinLoad and MaxLoad _________________________________________________ 76Surge Control _______________________________________________________________________ 77

How Surge is Detected _____________________________________________________________ 77Compressor Operating Methodology ____________________________________________________ 77

Accelerate-1______________________________________________________________________ 77Accelerate-2______________________________________________________________________ 78Slow Rolling ______________________________________________________________________ 78Quick Start Turbines _______________________________________________________________ 78

Operator User Interface (OUI) __________________________________________________________ 78Status Bar _______________________________________________________________________ 78System Folder ____________________________________________________________________ 78Info Folder _______________________________________________________________________ 78Settings Folder ___________________________________________________________________ 79

General Sequence of Operation ________________________________________________________ 80Starting Methodology ______________________________________________________________ 80

Diesel Driven Compressors _________________________________________________83

Communication _____________________________________________________ 84

Centac Energy Master (CEM) ________________________________________________84

Direct CMC Communications with RS422/485___________________________________84

The CMC-MODBUS Interface ________________________________________________85Introduction_________________________________________________________________________ 85Serial Modes _______________________________________________________________________ 85



MODBUS Messages _________________________________________________________________ 86Device Address ___________________________________________________________________ 86Function Code ____________________________________________________________________ 86Data Addresses ___________________________________________________________________ 86

Single Module Addresses _________________________________________________________ 87Multiple Module Addresses _______________________________________________________ 87

Data ____________________________________________________________________________ 87Byte Count _______________________________________________________________________ 87Cyclical Redundancy Check (CRC) ___________________________________________________ 87

Function Details_____________________________________________________________________ 87Function 01 - Read Coil Status_______________________________________________________ 87

Example: Reading a Single Coil ___________________________________________________ 88Example: Reading Multiple Coils __________________________________________________ 89

Function 02 - Read Input Status ______________________________________________________ 89Example: Read Single Discrete Input _______________________________________________ 90Example: Read Multiple Discrete Inputs_____________________________________________ 90

Function 03 - Read Holding Registers _________________________________________________ 91Example: See example for Function 04._____________________________________________ 94

Function 04 - Read Input Registers ___________________________________________________ 94Example: Read Single Channel 16-Bit Integer and Fraction _____________________________ 95Example: Read Single Channel IEEE 32-Bit Floating Point Number ______________________ 96Example: Read Multiple Channels _________________________________________________ 97

Function 05 - Force Single Coil ______________________________________________________ 97Example: Forcing a Coil _________________________________________________________ 98

Function 06 - Preset Single Register __________________________________________________ 98Example: Presetting a Single Register (16-bit) Integer _________________________________ 99

Function 15 (0F Hex) - Force Multiple Coils ____________________________________________ 99Example: Forcing Multiple Coils __________________________________________________ 100

Function 16 (10 Hex) - Preset Multiple Registers _______________________________________ 100Example: Presetting Holding Registers for 32-bit Values ______________________________ 101Example: Presetting a 16-bit Integer and 16-bit Fraction Holding Register ________________ 103

Exception Responses _______________________________________________________________ 103Function Code Field ______________________________________________________________ 104Data Field_______________________________________________________________________ 104Exception Codes Supported by the CMC Microcontroller_________________________________ 104

Maximum Query / Response Parameters _______________________________________________ 105CMC Data_________________________________________________________________________ 105Scaling and Units of Measure _________________________________________________________ 105Communication Parameters __________________________________________________________ 105

The CMC-DF1 Interface ____________________________________________________106Introduction________________________________________________________________________ 106Full-Duplex Protocol ________________________________________________________________ 107

DF1 Full-Duplex Protocol Message Frames ___________________________________________ 107DF1 Device Address ______________________________________________________________ 107Destination (DST) Byte ____________________________________________________________ 107Source (SRC) Byte _______________________________________________________________ 108Command (CMD) and Function (FNC) Bytes___________________________________________ 108Status (STS) Byte - Status Error Code _______________________________________________ 108Transaction (TNS) Bytes ___________________________________________________________ 108BCC (Block Check Character) and CRC (Cyclic Redundancy Check)_______________________ 108

BCC (One Byte) _______________________________________________________________ 109CRC (Two Bytes)_______________________________________________________________ 109

Data Addressing ___________________________________________________________________ 110




CMC as PLC5 ___________________________________________________________________ 110CMC as SLC5/04_________________________________________________________________ 111Data File Addressing for PLC5/SLC504 _______________________________________________ 111CMC Data Addressing_____________________________________________________________ 112

Supported Functions ________________________________________________________________ 116Command 0F/Function 68 - PLC5 Typed Read _________________________________________ 116

Example: Reading an Analog Input ________________________________________________ 116As 16-Bit Integer and Fraction ____________________________________________________ 117As IEEE 32-Bit Floating Point Number _____________________________________________ 118Example: Read Multiple Analog Channels __________________________________________ 119Example: Reading a Discrete Value _______________________________________________ 119Example: Reading Multiple Discrete Values ________________________________________ 120Example: Reading Bit-Packed Discrete Data________________________________________ 120

Command 0F/Function 67 - PLC5 Typed Write_________________________________________ 121Example: Presetting Analog Setpoints for 32-bit Values _______________________________ 121Example: Presetting a 16-bit Integer and 16-bit Fraction Analog Setpoint _________________ 123Example: Forcing a Coil ________________________________________________________ 123Example: Forcing Multiple Coils __________________________________________________ 124

Command 0F/Function A2 - SLC Typed Logical Read ___________________________________ 125Example: Reading an Analog Value _______________________________________________ 125Example: Reading Multiple Analog Values__________________________________________ 126Example: Reading Single Discrete Data____________________________________________ 126Example: Reading 16 Bit-Packed Discrete Data _____________________________________ 126

Command 0F/Function AA - SLC Typed Logical Write___________________________________ 127Example: Presetting Analog Setpoint for 32-bit Value_________________________________ 127Example: Presetting a 16-bit Integer and 16-bit Fraction Analog Setpoint _________________ 127Example: Forcing a Coil ________________________________________________________ 127Example: Forcing Multiple Coils __________________________________________________ 128

Allen-Bradley SLC 504 Example_______________________________________________________ 128Data Files_______________________________________________________________________ 128RSLogix 500 Ladder Diagram _______________________________________________________ 128

UCM STS Error Codes ______________________________________________________________ 129Communication Parameters __________________________________________________________ 130Network Setup _____________________________________________________________________ 1301770-KF2 Setup____________________________________________________________________ 132

SW-1 (Asynchronous Link Features)_________________________________________________ 132SW-2, SW-3, SW-4 (Node Address) _________________________________________________ 132SW-5 (Network Link Communication Rate) ____________________________________________ 133SW-6 (Asynchronous Link Communication Rate and Diagnostic Commands) ________________ 133SW-7 (Network Link Selection)______________________________________________________ 134SW-8 (RS-232C/RS-422A Selection) _________________________________________________ 134Wiring Diagram for RS-422A ________________________________________________________ 134

Documentation_____________________________________________________ 135

System Information _________________________________________________ 135

Status Codes_____________________________________________________________135

Base Control Module (BCM)________________________________________________137Module Layout _____________________________________________________________________ 137Connector Description _______________________________________________________________ 138Connector Input and Output (I/O) ______________________________________________________ 139

Operator User Interface Module (OUI) _______________________________________140



Module Layout _____________________________________________________________________ 140Connector Description _______________________________________________________________ 140Connector Input and Output (I/O) ______________________________________________________ 140CMC User Interface/Bezel Cleaning Instructions __________________________________________ 141Backlight Replacement Procedure _____________________________________________________ 141

Universal Communication Module (UCM) Optional_____________________________144Module Layout _____________________________________________________________________ 144Connector Description _______________________________________________________________ 145Connector Input and Output (I/O) ______________________________________________________ 145Setting UCM Switches ______________________________________________________________ 145UCM Port Activity LEDs _____________________________________________________________ 145UCM Communications Parameters ____________________________________________________ 146UCM Timeout ______________________________________________________________________ 146RS422/485 Network Wiring Diagram - Full Duplex ________________________________________ 147RS422 Network Wiring Diagram - Half Duplex ____________________________________________ 148Terminating Resistor ________________________________________________________________ 149Typical System Layout ______________________________________________________________ 149Network Diagram ___________________________________________________________________ 150

Technical Specification ______________________________________________ 151

Glossary ____________________________________________________________ 1

Service Tool Variable Names ___________________________________________ 7



Table of FiguresFigure 1: Compressed Air System ........................................................................................................4Figure 2: Autodual Control....................................................................................................................5Figure 3: Modulate Control ...................................................................................................................5Figure 4: Performance Control ..............................................................................................................6Figure 5: Proportional Band, Pb............................................................................................................7Figure 6: Proportional Plus Integral Control ............................................................................................8Figure 7: MinLoad and MaxLoad ...........................................................................................................8Figure 8: Rise To Surge ..................................................................................................................... 11Figure 9: Changes in Discharge Pressure ............................................................................................ 11Figure 10: Changes in Discharge Pressure .......................................................................................... 12Figure 11: Plant Air System ............................................................................................................... 35Figure 12: Troubleshooting Tree .......................................................................................................... 44Figure 13: MODBUS Messages ......................................................................................................... 85



1

What’s New In This ManualThis is the third version of the CMC Manual. This version was created to support newfeatures incorporated into the CMC Product, and provide additional information in generalcompared with the first and second versions.

Specifically, new features are as follows:

1. The basic compressor control logic has been refined to give even better pressurecontrol than before.

2. Surge AbsorberTM. This feature replaces Surge Reload and reduces the magnitude andduration of pressure variations for a surge cycle.

3. Gas and steam turbine driven compressor control with Adaptive StartingTM nowavailable as a standard option.

4. Diesel driven compressor control with Adaptive StartingTM now available as a standardoption.

5. Event log has been expanded to 224 events all scrollable from the OUI. New eventshave been added for surge, turbine operation, multiple board failure and controlparameter edits from both local or remote control locations. This added information isinvaluable for troubleshooting.

6. Allen-Bradley DF1 communication protocol has been added for connection to DataHighway Plus (DH+) networks.

7. More data available is available at a faster rate from a single communication read.

8. Three module support. This allows systems to contain as many as 69 analog inputs, 3CT inputs, 3 speed inputs, 12 analog outputs, 48 discrete inputs and 48 discreteoutputs.

9. Added math capabilities allow for more options.

10. The OUI has been updated to enhance the overall look and feel and ease of use. TheCoasting Timer and BCM Version have been added.

11. New fonts have been added for Russian, Arabic and Greek.

12. New diagnostic feature for Motor Failure Trip. This helps in troubleshooting compressorstarting problems.

13. Derivative constants for the Inlet Valve Pressure, MinLoad and MaxLoad PID controlloops along with the Bypass Valve Pressure PID control loops have been added to theOUI, this feature provides a higher level of tuning capabilities for the knowledgeableUser.

2 CMC TECHNICAL REFERENCE MANUAL



ReferencesThe following references were used in creating this document. All of this documentation isrecommended for a more detailed understanding of specific control modes and controlpanel functions.

NEMA STANDARDS PUBLICATION NO. 250, Enclosures for Electrical Equipment (1000 VoltsMaximum), Revision 2, May 1988

NFPA 496 Standard for Purged and Pressurized Enclosures for Electrical Equipment, 1986Edition

Nisenfeld, A. Eli, Centrifugal Compressors: Principles of Operation and Control, InstrumentSociety of America, 1982

Moore, Ralph L., Control of Centrifugal Compressors, Instrument Society of America, 1989

Doebelin, Ernest O., Control System Principles and Design, John Wiley & Sons, 1985

Rowland, James R., Linear Control Systems Modeling, Analysis, and Design, John Wiley &Sons, 1986

Deshpande, Pradeep B. and Ash, Raymond H., Computer Process Control With AdvancedControl Applications, 2nd Edition, Instrument Society of America, 1988

CENTAC ENERGY MASTER, Version CEM230, Ingersoll-Rand Company, March 1992

White, M.H., Surge Control for Centrifugal Compressors, Chemical Engineering, December 25,1972

Hall, James W., THERMODYNAMICS OF COMPRESSION: A Review of Fundamentals,Instrument Society of America, 1976

Gaston, John R., Centrifugal Compressor Operation & Control: Part II "Compressor Operation",Instrument Society of America, 1976

Gaston, John R., Antisurge Control Schemes For Turbocompressors, Chemical Engineering,April 1982

Warnock, J. D., Methods for Control of Centrifugal and Reciprocating Compressors, MooreProducts, 1984

Harrison, Howard L. and Bollinger, John G., Introduction to Automatic Controls, Second Edition,Harper & Row, 1969



3

General - CMC PanelThe CMC panel is the microprocessor-based control and monitoring system for Centac andX-FLO centrifugal compressors. The CMC handles all pressure control and monitoringfunctions; as well as, control auxiliary equipment such as the main motor starter, oil heater,and prelube pump.

The CMC panel has a custom designed computer board called the Base Control Module(BCM). This board has a microcontroller and memory chips that tell the rest of the panelwhat to do for the various input pressures, temperatures and vibrations. All hardware fordata analysis, number of input and output (I/O) points and system memory are optimallyselected for accurately controlling and protecting Centac and X-FLO compressors.

Features of the CMC system are:

• Ease of use ... only twelve buttons to push on the operator OUI!

• Multiple function, 240 x 128 pixel graphic LCD display to display data and operating status

• Unload, Modulate and Auto-Dual operating modes.

• Advanced surge detection and control.

• High current limit for main drive electric motor protection.

• First-out indication and event log to help determine the root cause of a compressor trip.

• Pinion vibration alarm and trip for each compression stage.

• Optional port for communicating to the Centac Energy Master (CEM) or other DistributedControl Systems (DCS) via MODBUS protocol.

• Optional reduced voltage motor starter included in panel for some sizes.

NOTE

For the purpose of consistency and clarity, all of the descriptions and examples thatfollow refer to "air" for the more generic "gas". Any gas compressed by a Centac or X-FLO compressor would also apply.




Control MethodologyThe CMC utilizes performance and surge control methodologies to meet varyingcompressed air system needs. The term "performance control" is used for grouping thecontrol modes that affect compressor power consumption through movement of the intakeand discharge valves.

Performance ControlThe CMC has three standard performance control modes or methods of operation. Thesemodes are Unload, Modulate and Autodual for typical plant air compressors operating inconstant pressure applications. For the discussions that follow, Figure 1 depicts acompressed air system and the relationship between the compressor and the plant airsystem.

Compressor

Plant Air SystemInletValve Bypass

Valve CheckValve

InletFilter

Silencer

Atmosphere

Figure 1: Compressed Air System

UnloadThe compressor is unloaded, when no air is being supplied to the Plant Air System, and allof the air produced by the compressor is being vented to the atmosphere. In this mode, theinlet valve is slightly open to allow enough air to pass through the compressor for internalcooling, prevention of rotor instability and surge avoidance. This air is then dischargedthrough the fully open bypass valve to the atmosphere. Typically, the compressor is set tomake a positive pressure across the first compression stage, which produces a dischargepressure something greater than the atmospheric pressure.

The inlet valve opening required to create this positive pressure is directly related to thehorsepower consumed; therefore, careful consideration should be given to this inlet valveposition for minimizing overall power consumption.

Constant Pressure Control - ModulateConstant pressure control is a frequently required performance control method for Centacair compressors. If left uncontrolled, the compressor's discharge pressure would rise andfall along the natural performance curve as system demand changed. Modulate controlsatisfies the constant pressure requirement.

The performance map in Figure 2 shows Modulate control. Modulate maintains the systemdischarge pressure at the system pressure set point as entered into the CMC by the user.



5

Once loaded, the compressorwill operate along the constantpressure line until the userswitches to Unload or pressesthe stop button.

Control is accomplished bymodulating the inlet valve withinthe compressor's throttle range.When system demand is lessthan the minimum throttledcapacity, the dischargepressure is maintained bymodulating the bypass valve andventing some or all of the air toatmosphere. This valve isopened just prior to reaching thesurge line. Whenever thebypass valve is open, the inletvalve maintains its position atthe minimum throttled capacitysetting. Modulate provides aconstant discharge pressurewith variable capacity from

design to zero.

This control method is usedwhen reliable control of thedischarge pressure is required.Modulate is the most commonlyused control method for Centacand X-FLO compressors.

Energy Saving Control - AutodualAutodual automatically loads themachine when demand is highand unloads the machine whendemand is low.

When the compressor iscontrolling to pressure setpointand demand is within the inletvalve throttle range, constantpressure is maintained in thesame manner as Modulate.

When the machine is controllingto the pressure setpoint andsystem demand is low, thecompressor is operated in thebypass valve throttle range.

DischargePressure

Power atCoupling

Capacity

Surge LineNaturalCurve

DesignPoint

NaturalCurve

UnloadPoint

Unloaded

Unloaded

InletValve

ThrottleRange

BypassValve

ThrottleRange

Reload Point(Reload Percent)

UnloadPoint

Figure 2: Autodual Control

DischargePressure

Power atCoupling

Capacity

InletValve

ThrottleRange

Surge Line

NaturalPressureCurve

DesignPoint

MaximumThrottle Point

(MinLoad)

Constant Pressure Line

Unloaded

BypassValve

ThrottleRange

NaturalPowerCurve

Surge Line

Constant Power Line

Unloaded

Figure 3: Modulate Control




Autodual automatically unloads the machine when the bypass valve is opened beyond theUnload Point for a programmed time period called the Unload Delay Time. The BypassValve Unload Point is selected to correspond with the check valve closing since at this pointthe machine is not supplying the system (Figure 1). The Unload Delay Timer should be setto prevent unloading during short excursions through the Unload Point. The Reload Percentdetermines the System Pressure at which the machine will automatically load into thesystem.

How does Constant Pressure Modulation Work?The goal of constant pressure modulation is to maintain a specified discharge pressure inthe compressed air system while the capacity requirements change. Modulate controlprovides constant pressure from 100 percent of the compressor's capacity to zero capacity.Autodual control provides constant pressure from the 100 percent of the compressor'scapacity to the Unload Point.

If all plant air systems were identical in capacity usage requirements, the CMC could bepreprogrammed to respond to those changes; however, all plant air systems are not alike.The frequency and variability of the capacity changes means that the control logic must beflexible, so the CMC utilizes proportional plus integral control algorithms to determine themagnitude of the signal that is sent to the inlet and bypass valves. These algorithms, orprogramming logic, allow the CMC control system to be "tuned" to a specific plant airsystem.

Measuring the Discharge PressureIn order to maintain constant pressure, the system discharge air pressure must bemeasured. A pressure transducer is mounted in the control panel and tubed to thecompressor discharge downstream of the check valve as shown in Figure 4.

CompressorMotor

StarterCT

BypassValve

InletValve

CheckValveBase

ControlModule

PT

4-20 mA

4-20 mA

CMCPneumatic Tubing

Figure 4: Performance Control

This transducer sends a 4-20 mA signal to the CMC board. The CMC compares themeasured discharge pressure to the system pressure set point entered into the CMC by theuser through the Operator User Interface (OUI). Depending upon the difference betweenthese two values the CMC will send a 4-20 mA signal to "Modulate", open or close, the inletand/or bypass valve to maintain the specified system pressure set point.



7

Proportional BandProportional control varies the signal sent to the valves as a linear response to thedifference between the actual system pressure and the system pressure set point. Valveresponsiveness can be adjusted through the CMC with the proportional band, Pb, set point.This scaling factor, graphically depicted in Figure 5, is the amount of change in the inputvariable (actual minus set point pressures) to cause a full scale change in the outputvariable (valve position).

In other words, if the pressure in the air system fluctuates frequently, it would be prudent toset Pb to a low value to keep up with those system changes. Otherwise, if the system isvery stable, a larger value can be used. Pb is directly related to valve life and indirectlyrelated to valve cycling; so, as Pb decreases, valve life decreases and cycling increases.

As stated earlier, the CMC uses a proportional plus integral control algorithm. The result ofproportional only control is offset from the controlled variable, discharge pressure. Thismeans that if the set point pressure is 100, the actual pressure may only be 95. The value ofthis offset depends upon the proportional bandvalue.

What is the valve response when the differencebetween actual and set point pressures is zero?There is no response. Proportional control onlyfunctions when a difference or error exists. Designdischarge pressure could not be attained in aproportional only control system. Therefore, anintegral control algorithm is added to achieve thedesired discharge pressure.

Integral TimeThe offset produced by the proportional controlalgorithm could be eliminated by manuallyreadjusting the system pressure set point. Usingthe example above, the set point could be reset to105 to obtain the 100 desired. Manually resettingthe set point would be required as the systemdemand fluctuated. Integral control, also known asreset control, automatically resets the desiredsystem pressure set point. For the CMC, the rateat which the controller resets the system pressuresetting is known as Integral Time, It, and isexpressed in units of repeats per second.

If precise control of the specified dischargepressure is required, the It set point should be setfor a fast value. It is inversely related to valve lifeand directly related to valve cycling, therefore, as Itdecreases, valve life increases and cyclingdecreases. For the CMC controlling Centac and X-FLO compressors, It values are typicallyless than 1.00.

OutputVariable

(Valve Position)

Pbhigh

Full Scale

0

Large Change

OutputVariable

(Valve Position)

Input Variable(Actual - Set Point Pressures)

PblowFull Scale

0

SmallChange

Slow

FastResponse

Response

Figure 5: Proportional Band, Pb




Figure 6 shows therelative valve responseover time for twocombinations of Pb and It.As shown, when Pb is lowand It is fast, valve activityis significant in bothmagnitude and frequencyto obtain the desired setpoint. The other scenario,Pb is high and It is slow,has relatively little valveactivity, and may neverreach the set pointposition.

Proportional Band andIntegral Time arevariables used internallyby the control system todetermine valve responseand direction for a givencompressed air system. Each has anoptimum value based upon thesystem's characteristics. Determiningthese optimum values is a trial anderror exercise. These set points shouldbe re-evaluated any time there is amajor change in the compressed airsystem.

Up to this point, constant pressurecontrol has been accomplished with ananalog input (system pressure) and twoanalog outputs (inlet valve and bypassvalve position). How is motor current,the other analog input, used forconstant pressure control? When doesthe bypass valve modulate as opposedto the inlet valve?

Motor Current, MinLoad and MaxLoadMotor current, in units of power(normally amps), has two functions inthe CMC. The first is over currentprotection for the main motor, and isreferred to as MaxLoad or High LoadLimit (HLL). The second functiondetermines the point at which thebypass valve begins to modulate for

Time

ValveActivity

Proportional Band - LowIntegral Time - Fast

Proportional Band - HighIntegral Time - Slow

Closed

Opened

Set Point

Figure 6: Proportional Plus Integral ControlD

isch

arge

Pre

ssur

eP

ower

at C

oupl

ing

Capacity - Mass Flow

Min

Load

Max

Load

Thot

Tcold

Figure 7: MinLoad and MaxLoad



9


Power atCoupling

Amps

DischargePressure

TL

HLL

Inlet ValveMaxLoad PIDControl Zone

Inlet ValveMinLoad PIDControl Zone

Inlet ValvePressure PIDControl Zone

Bypass ValvePressure PIDControl Zone

controlling pressure. This point is called MinLoad or Throttle Limit (TL). The location of thesetwo points is graphically depicted on the pressure and power versus capacity curves asshown in Figure 7.

MaxLoad or High Load Limit (HLL) setpoint, in units of amps, is a parameter entered intothe CMC that prevents the main drive motor from overloading. Once this value is reached,the CMC logic limits the inlet valve from opening any further. This action constrains themotor by limiting the amp draw to the maximum allowable service factor amps by using theinlet valve MaxLoad PID loop to maintain the MaxLoad current setpoint.

When the motor is sized for cold conditions, there are circumstances when MaxLoad willnever be reached. For example, the value of MaxLoad as shown in Figure 7, cannot beattained for the T=hot curve because it is beyond the maximum compressor capability; that

is, the inlet valve is fullyopen. This scenarionever limits the inletvalve.

When ambientconditions produce theT=cold curve, thecompressor will not beable to achieve themaximum capacitybecause it is beyondthe MaxLoad value.Since MaxLoad is lessthan or equal to themotor nameplate FLAtimes the adjustedservice factor, themaximum compressorcapacity at T=coldcould only be reachedif the motor were sizedfor the T=coldcondition.

MinLoad ControlSetpoint in units ofamps is the powervalue at which the

CMC transfers modulation control from the inlet to the bypass valve. The reason for thistransfer is to prevent the compressor from entering into a surge condition. The bypass valvevents air to the atmosphere and maintains the pressure setpoint by using the bypass valvepressure PID loop. At the same time, the inlet valve maintains the MinLoad setpoint byusing the inlet valve MinLoad PID loop; therefore, once the MinLoad setpoint is reached,the compressor continues to produce a constant amount of air. Part of this air goes to thePlant Air System, and the remainder is blown off. Even though the Plant Air System receivesonly a portion of the air produced, the amount of power remains constant.




The following table presents seven capacity requirements for a plant air system. At each ofthe capacities, the table shows the compressor output, valve position, discharge pressureand power. Each of these values represents a percentage and is only an example. P2 is thespecified discharge pressure and P0 is the barometric pressure.

From the table above, once the system required capacity moves below 75 percent, thecompressor still produces 75 percent capacity with 80 percent of the power. If the systemneeds only 25 percent capacity, it will still have to pay for 80 percent of the power. This iswhy it is important to open the bypass valve at the last possible moment; therefore, settingMinLoad properly is critical for efficient energy management.

Surge ControlSurge is the reversal of flow within a dynamic compressor that takes place when thecapacity being handled is reduced to a point where insufficient pressure is being generatedto maintain flow. This condition can potentially damage the compressor if it is severe and isallowed to remain in that state for a prolonged period; therefore, control and prevention isrequired.

Control MethodologySurge prevention is accomplished by opening the bypass valve prior to reaching the surgepoint. The point at which the bypass valve opens is MinLoad. By blowing a portion of the airto the atmosphere, the compressed air system gets the air that it demands. Thecompressor avoids surge because it is still producing a constant air capacity.

Surge DetectionEven though the CMC controls to prevent surge, it can still occur. Insufficient rise to surge,rapid changes in system discharge pressure, and various other reasons exist for acompressor to surge.

Insufficient Rise To SurgeRise to surge is the percentage of the compressor's surge pressure to discharge pressure(see Figure 8). When an insufficient rise to surge situation exists, small fluctuations in theair system demand and ambient temperature can cause the compressor to surge.

From Figure 8, when T=cold, there is sufficient rise to surge. As the ambient temperatureincreases to T=hot, the amount of rise to surge decreases because the discharge pressureis remaining constant and the natural curve is changing with temperature.

System Compressor Compressor

Open Position

Required

Capacity

OperatingState

OutputCapacity

InletValve

BypassValve

DischargePressure Power

0 Off 0 0 100 0 00 Unloaded 10 10 100 >P0 20

100 Full Load 100 100 0 P2 100

75 MinLoad 75 70 0 P2 80

50 MinLoad 75 70 25 P2 80

25 MinLoad 75 70 50 P2 80

0 MinLoad 75 70 100 P2 80



11

Typically sufficient rise to surgeexists when a ten- percent riseto surge can be achieved for thehottest ambients that areexpected for the site. If thisdesign criterion is followed, thecontrol system should be ableto prevent surge for variations inair demand and inlettemperature. The same designmethodology applies forchanges in cooling watertemperature for multi-stagecompressors.

Changes in System Discharge PressureMinLoad corresponds to a specificconstant discharge pressure;therefore, if the discharge pressurechanges, MinLoad must be reset toproperly control surge. As shown inFigure 9, when the dischargepressure is changed from point 1 to2, a surge can occur at point 2 ifMinLoad is not reset.

Changes in system dischargepressure also apply, but more subtly,when the compressor begins to age.Dirty inlet filter elements and fouledcoolers can change thecompressor's natural curve; soMinLoad should be checkedperiodically to prevent surge from anincorrect setting.

Rapid System Demand ChangesWhen the system demand varies rapidly over a wide range of capacity, the controller maynot react fast enough to open the bypass valve to prevent surge. The CMC reads dischargepressure, motor amps, and approximately twenty other pressure and temperature inputs;plus controls the inlet and bypass valve position. The time required to do all of thisapproximately 100 milliseconds. When the controller is too slow to react, it is referred to as"driving through MinLoad". The only prevention for a situation like this is to set MinLoad at amore conservative value. The only negative implication to this is reduced energy savings,because the bypass valve is opened early.

Incorrect Instrumentation OutputIf the instrumentation, defined in Figure 4, is improperly calibrated or gives inaccuratereadings, the compressor could surge even though the CMC thinks it should not. Areas of

Capacity

DischargePressure

RiseTo

Surge

T=cold

T=hot

Figure 8: Rise To Surge


DischargePressure TL1

TL2

Figure 9: Changes in Discharge Pressure




concern are insufficient power air, incorrect valve transducer calibration, and repeatability ofboth inlet and bypass valves. If the valves are being sent signals for specific movementsand they do not respond by moving to the new positions, then the CMC has very littlechance of correctly controlling surge, or even the discharge pressure.

As discussed earlier, the CMC uses motor current as the standard method for determiningwhen to open the bypass valve. The time to begin opening the bypass valve is nearMinLoad amps. The equation,

GHPI V PF

motor=× × × ×η 3

746indicates that horsepower is directly related to current; it is, but it is also related to voltage.This is not normally a concern because voltage is primarily constant. However, there aresome locations where extreme voltage variations do exist. In these circumstances, the CMCcannot correctly determine when it reaches MinLoad and a surge can occur. For theseapplications, an optional watt transducer can be used to avoid this situation.

How is Surge Detected?Note that it has been shown that even though the CMC has surge prevention logic, a surgecan still occur. The CMC has a surge detection system comprised of a surge pressuretransducer and motor current transformer (see Figure 10). The CMC senses surge whenthe rate of change in last stage discharge pressure and the rate of change in motor currentare greater than the surge sensitivity setpoint value. When this occurs, the CMC will alarmand unload the compressor.

Figure 10: Changes in Discharge Pressure

Surge AbsorberTMWhen the controller recognizes that a surge occurred, the compressor will unload. With theSurge AbsorberTM feature enabled, the controller will increment the bypass valve position bya fixed percentage, send the inlet valve to the MinLoad point (if it is not already there) andthen let normal system demand reload to the operating pressure. This process will repeatup to three times within a ten-minute period. If the compressor surges four times in tenminutes, the compressor will remain unloaded until an operator presses the reset button.Each detected surge drives a Surge Event to the Event Log. If the compressor unloads doto repeated surges, a Surge Unload Alarm Event is driven to the Event Log.

CompressorMotor

StarterCT

BypassValve

InletValve

CheckValveBase

ControlModule

PT

4-20 mA

4-20 mA

CMCPT

Pneumatic Tubing



13


Power atCoupling

Amps

DischargePressure

MinLoad User Setpoint(reset returns control here)

MinLoadSurgeIndex

Increment

MinLoad Control Setpoint

MinLoad Control Setpoint #1

MinLoad Control Setpoint #1

MinLoad Control Setpoint #3(currently active)

Surge IndexingSince the setting of MinLoad Control Setpoint is sensitive to many variables in acompressed gas system, there is potential for the setting to require adjustment throughoutthe operation of the compressor. When MinLoad is set incorrectly, one of two things canhappen. When MinLoad is set too high, the compressor will consume excessive power atMinLoad. When MinLoad is set too low, the compressor is allowed to go past the surge lineand surge occurs.

When Surge Indexing isenabled, it corrects thesituation when MinLoad isset too low by automaticallyadjusting MinLoad to ahigher value upon a surge.The indexed setting,MinLoad Control Setpointwill remain in effect untilMinLoad User Setpoint ismanually changed on theOperator User Interface, orthe Reset button is held formore than five seconds.When MinLoad UserSetpoint is manuallychanged, the MinLoadControl Setpoint isautomatically changed to

match the new setting and when reset the MinLoad Control Setpoint is reset to the originalMinLoad.

Entering a non-zero number into the MinLoad Surge Index Increment variable enables surgeIndexing.




Oil System ControlThe CMC panel provides control of the prelube pump and lube oil heater in the startingsequence, during normal operation and after compressor stops or trips.

Prelube PumpThe prelube pump is started when the panel power is on and Seal Air is present. Theprelube pump stops after the compressor start button is pushed and the programmabletimer “Start Time” has expired. The pump does not come on again until the Stop key ispressed, and will remain on until the panel power is turned off or Seal Air is lost.

Oil HeaterThe oil heater is thermostatically controlled. When the oil temperature is below the set pointtemperature, the oil heater is energized, above the set point temperature it is de-energized.The oil heater control does not have any interaction with the microprocessor board and isdesigned to operate with the control panel de-energized as long as three-phase power isavailable.



15

Protection and MonitoringEach CMC base module has twenty-three analog inputs, sixteen digital inputs, four analogoutputs and sixteen digital outputs for control, protection and monitoring. These inputfunctions provide the CMC with information about the compressor. The CMC board uses theoutput functions to communicate to the user and perform actions like starting thecompressor and turning on the prelube pump. All of these inputs and outputs are required tointerface physical actions to and from the electronics.

Analog FunctionsAn analog function is one in which an electrical signal represents a specific pressure,temperature, vibration and current input; or valve position output. As these inputs andoutputs fluctuate, the electrical signal to and from the microprocessor board also fluctuatesproportionally to the amount of change.

Analog InputsTwenty-one grounded and two floating analog inputs are used for protection, monitoring andcontrol. Each input used for protecting the compressor is programmed for alarm and tripindication. Each of these functions is pre-programmed with the function title, engineeringunits, range, alarm and trip values, so no configuration is required upon receipt by thecustomer.

The CMC uses pressure transmitters to measure pressure, resistance temperaturedetectors (RTD) and transmitters to measure temperature, eddy current based vibrationtransmitters to measure shaft vibration and a current transformer to measure the motorcurrent.

The CMC logic used for the protective alarm and trip functions is as follows: if the actualvalue of the input is greater than or equal to the alarm or trip value, indicate the condition.This logic is used for all inputs except, low oil pressure and temperature where the logic isreversed. To prevent nuisance alarms and trips, all standard analog inputs use an alternatealarm and trip value during the stopped, starting, and coasting states. The alternatesetpoints cannot be edited through the Operator User Interface.

Analog OutputsTwo of the available four analog output functions are for inlet and bypass valve positioning.These are only output functions. The standard configuration for a CMC has no inputinformation as to the valve location. The CMC calculates the position based upon where thevalves are supposed to be and sends those signals to the valves.

Digital FunctionsA digital function is one in which the presence of an electrical signal indicates ON or YES,and the lack of that signal represents OFF or NO. This is analogous to a light switch thathas only two states, ON or OFF. The term "discrete" is also used instead of digital in manyinstances. The term that will be used throughout this documentation shall be digital.

Digital InputsThe sixteen digital inputs provide status of field switches. Emergency Stop and Low Seal AirPressure trip are standard. Any of these inputs can be configured as an alarm or trip. Allinputs operate on 24 VDC power.




Digital OutputsThe sixteen digital outputs are used by the CMC to start the prelube pump, energize themain starter contacts, indicate that an alarm or trip condition exists, indicate that thecompressor is unloaded, activate the running unloaded shutdown timer and to sound thehorn. Outputs can operate on 120 VAC, 60 Hz, single-phase power or 24 VDC power.



17

Compressor Operating StatesMotor Driven Packages

Stopped+

Waiting

Not Ready

Ready

Compressor+

+ Rotating

Starting

Loading

Unloaded

MinLoad

LoadedFull Load

MaxLoad

A-D Unloaded

Surge Unload

Unloading

Coasting

Compressor Operating MethodologyIn the following description of compressor operation, the term “state” is used to indicatewhat the compressor is doing, or mode of operation, at any given time. These operatingstates exist in a hierarchy. For example, the two highest level states are “Stopped” and“Rotating”. All other states exist at a level below these two states.

StoppedThis state implies that the compressor is orNOT rotating. It is important to note that thisis an implication only. If the instrumentation isnot working properly or the system is setupimproperly, the compressor could be rotating.

WaitingAfter the panel power is energized, thecontroller starts the Waiting Timer and doesnot allow further User operation until after thetimer expires. This timer is set at the factoryfor two minutes (120 seconds) and is notadjustable. This period allows thecompressor prelube pump to circulate oilthroughout the casing and prevents restartingwhile the compressor is coasting downduring an electrical interruption.

Not ReadyWhen in this state, the compressor is “NotReady To Start”. This state is entered whenthe Waiting Timer has expired and any timethat a compressor trip has been identified ora stop command has been issued. A very

common and quite often overlooked reason for the compressor being “Not Ready” is whenthe Emergency Stop push button has been engaged. This state can exist indefinitely.

ReadySimilar to the previous state, this state could be redefined as “Ready to Start”. This state isentered when all compressor permissive functions have been satisfied. This state can existindefinitely.

RotatingThis mode does not necessarily mean that the compressor is actually rotating. It means thatit is rotating or rotation is pending and expected.

StartingAny time after the compressor is ready and a start command is given, this state is entered.The goal for this period is to get the compressor to rated speed and running unloaded.“Starting” is allowed for only the Start Timer period and is adjustable. This time period is




limited to a maximum of one minute, or 60 seconds. The reason for the limit is to preventthe compressor from operating in the critical speed for an extended period. Stage vibrationalarm and trip setpoints are increased during this period to get the compressor through thecritical speed region. After the compressor has “Started”, the alarm and trip setpoints areadjusted back to their original values. The same procedure occurs for stage air temperaturealso.

This state exits only after the Starting Timer has expired. THE COMPRESSOR IS ALWAYSSTARTED UNLOADED. On exit of “Starting”, the compressor will return to the mode that itwas in the last time it ran. For example, typical operation implies that prior to stopping thecompressor, the Unload key is pressed. If this occurred, then the compressor will remain in“Unload” after starting. If the compressor is was running and tripped, the compressor willautomatically return to the “Loaded” mode on exit of the Starting state. The User may alsopress the Load or Unload key prior to pressing the Start key to force the compressor to intoeither post-Starting state.

UnloadedThe compressor is in this state after a start (and Load Selected is not in effect) or when theUser issues an unload command. A-D Unloaded and Surge Unload are also consideredstates. However, these two states are really just reasons for being in the Unloaded state. A-D Unloaded means “AutoDual Unloaded” which occurs when AutoDual is enabled and thesystem pressure has been high enough for a long enough time to drive an unloadcommand. “Surge Unload” is similar in that a surge event drives the unload commandinstead of AutoDual. These states can exist indefinitely.

LoadingWhen a valid load command is issued, the compressor will enter this state. This stateexists until the MinLoad state is satisfied. The duration of this state depends upon PIDsettings for the inlet valve at the MinLoad state and the demand for air.

MinLoad, Loaded, Full Load and MaxLoadThese states transition among themselves as demand for air changes. “MinLoad” meansthat the bypass valve is controlling pressure and the inlet valve is maintaining the MinLoadControl Setpoint. “Loaded” means that the inlet valve is controlling pressure and the bypassvalve is closed. “Full Load” occurs when the inlet valve has reached the full open or 100%position. “MaxLoad” means that the inlet valve is maintaining the MaxLoad Setpoint toprevent motor damage. In both the “Full Load” and “MaxLoad” states, system pressure willbe lower than setpoint pressure.

UnloadingThis state occurs when a valid Unload command is issued and will persist until thecompressor reaches the Unloaded state.

CoastingWhen a trip or any stop command is issued and the compressor is running, the motor willbe de-energized and the compressor will begin to coast to a Stopped state. This state willremain as long as the adjustable Coast Timer is in effect. At the end of the timer, thecompressor will enter either the Ready or Not Ready state.



19

WARNING

Failure to set the Coast Timer for a period greater than or equal to the actualcoasting time can result in compressor damage.

Compressor Operating StatesThe following diagrams graphically depict the states relative to valve position. This diagramsis provided to assist in the understanding of overall compressor operation.

Un

load

ed

Co

asti

ng

Sta

rtin

g

Lo

adin

g

Lo

aded

Min

Lo

ad

Fu

ll L

oad

Lo

aded

Max

Lo

ad

Un

load

ing

Un

load

ed

20

Compressor Operating Stateswith Valve Position

RotatingStopped

4

16

12

8

100

0

75

50

25

No

t R

ead

y

Rea

dy

Wai

tin

g

Start

100

0

25

20

4

8

12

16

BypassValve

50

75

milliamps

%

PowerOn

InletValve

milliamps

%

Tight Closure

Inlet Valve Unload Position

Load

Unload

System Pressure Setpoint

System Pressure




User Interface

OUI (Operator User Interface)User interface is defined as the means by which people interact with the compressor controlsystem. The standard configuration of the CMC has two components of the user interface.They are the OUI and the device plate. The key component of "easy to use" is that there areonly twelve buttons to press on the OUI and four buttons, lights, and switches on the deviceplate.

The CMC OUI consists of six command buttons (Start, Stop, Load, Unload, Acknowledgeand Reset), four navigation keys (Up, Right, Left and Down), an Edit mode selection key(Enter) and a Contrast key. These keys in conjunction with the 240x128-pixel graphicsdisplay make up the user interface to the compressor. The bezel that surrounds the OUIensures that the NEMA 4 rating is maintained for the OUI.

CENTAC Microcontroller

1/2

SETTINGSINFO

MotorCurrent

SystemPressure

PressureSetpoint

105.3105.0173.4

Loaded

InletValve

BypassValve

950

RemoteLoad Selected

22JUL96 12:00:00

SYSTEM

Running Hours 11445



21

Command KeysThese keys “command” the compressor to perform actions as specified in the followingtable. When any of these keys are pressed the action will be logged in the event log.

Enter Key - Display Operating ModeThe Enter key toggles the display between the NAVIGATION mode and the EDIT mode.

Navigation KeysThe arrow keys for Up, Right, Left and Down perform differently depending upon the currentdisplay-operating mode.

FOLDER NAVIGATION

To move among the tabbed folders, press the RIGHT or LEFT key. The folder list is circular;that is, when the SYSTEM folder is displayed and the LEFT key is pressed, the SETTINGSfolder becomes active. The same is true when the SETTINGS folder is displayed and theRIGHT key is pressed, the SYSTEM folder becomes active.

PAGE NAVIGATION

To move among each folder’s pages, press the UP and DOWN keys. The page list is alsocircular. So, when page 1/4 (pronounced page 1 of 4) is active and the UP key is pressed,page 4/4 becomes active. Also, when page 4/4 is active and the DOWN key is pressed,page 1/4 becomes active. The current page for a folder is persistent. For example, if youbegin on the SYSTEM folder page 2, change to the INFO folder and return to the SYSTEMfolder, page 2 will be the page displayed.

Key Name Function

AcknowledgeSilences the optional horn oracknowledges an alarm.

ResetClears all trip latches. Required to bepressed after a trip condition to restartthe compressor.

StartStarts the compressor.

StopStops the compressor. This buttonshould be pressed instead of the E-Stopfor normal operation.

LoadEngages Modulate or Autodual controlmode.

UnloadUnloads the compressor.




Contrast KeyThis key changes the contrast of the backlight for the graphic LCD display. Pressing this keysteps among each of the sixteen contrast levels. When stepped to the sixteenth level,pressing the key again returns to the first contrast level.

Graphic DisplayThe 240x128-pixel graphic display allows us to provide a flexible interface between the userand the compressor. The display has three distinct regions as shown in the diagram below.

Folder and PageIn the design of this system, it is important to provide much of the information required foroperating and troubleshooting the compressor. The tabbed folder with multiple pagesmetaphor has been used to reduce the complexity of a traversing at least ten pages ofinformation. For the standard design, the maximum number of keys required to get to any ofthe ten pages is four. The SYSTEM folder provides information about the compressorsystem, the INFO folder gives various types of information about the unit and the SETTINGSfolder is used to perform compressor setup.

Status BarThe Status Bar provides four distinct types of information (Compressor Operating State,Compressor Status, Compressor Control Location and Page Number). This region isalways visible from any folder and page combination.

This Field is displayed in large text so that the operator can determine the compressor’scurrent operating state at a glance. See Section titled “Compressor Operating Methodology”for a list of the messages provided.

The Compressor Status Field messages are Trip, E-Stop (emergency stop buttonpressed), RMT-Stop (a remote stop has been pressed), Start Disabled (an optionalpermissive start condition has not been satisfied), Alarm, Unload Selected (thecompressor will stay in “Unload” after “Starting” has been completed), and Load Selected(the compressor will go to “Minload” after “Starting” has been completed).

1/2

SETTINGSINFOSYSTEM

MotorCurrent

SystemPressure

PressureSetpoint

105.3105.0173.4

Loaded

InletValve

BypassValve

950

RemoteLoad Selected

22JUL96 12:00:00

Page

Status Bar Page Number

CompressorControl

Location

CompressorOperating

State

Folders

CompressorStatus

Graphics Display Area Definitions



23

The Compressor Control Location Field messages are Local, Remote (remote hardwiredcommands i.e. start, stop, load, unload etc.), Network (MODBUS, DF1 or CEMcommunication with a UCM) and Remote/Net (both Remote and Network). This indicationis provided to indicate to the operator that a remote location is in control of the compressorand the compressor may start, stop, load, unload, etc. without the local operator initiatingany commands.

These three fields combine to provide the operator with the necessary information to createa cursory determination of the status of the compressor. When a more thoroughdetermination is required, the operator can get additional detail by looking through the otherpages in the system.

The Page Number indicates the current page for the current folder with the number of pagesin the folder. The number of pages is given so that the user always knows where he is in thesystem.

Edit (Setpoint Changes) ModePressing the Enter key to toggle from Navigation to Edit mode can change Setpoints for apage. Once in this mode, the highlight will move from around the folder name to item to bechanged. Use the Right and Left arrow keys to move among the changeable items and theUp and Down arrow keys to change the value of the item. When changes are complete,press the Enter key again to return to Navigation mode.

Navigation ModeNavigation mode is active when a folder name (SYSTEM, INFO or SETTINGS) ishighlighted. When inactive, press the ENTER key to activate.




INFO Folder SETTINGS Folder

Navigation andEnter Keys

NAVIGATION MODENavigation mode is active when a folder name (SYSTEM,INFO or SETTINGS) is highlighted. When inactive, press theENTER key to activate.

FOLDER NAVIGATIONTo move among the tabbed folders, press the RIGHT orLEFT key. The folder list is circular; that is, when theSYSTEM folder is displayed and the LEFT key is pressed,the SETTINGS folder becomes active. The same is truewhen the SETTINGS folder is displayed and the RIGHT keyis pressed, the SYSTEM folder becomes active.

PAGE NAVIGATIONTo move among the pages, press the UP and DOWN keys.The page list is also circular. So, when page 1/4 (page 1 of4) is active and the UP key is pressed, page 4/4 becomesactive. Also, when page 4/4 is active and the DOWN key ispressed, page 1/4 becomes active. The current page for afolder is persistent. For example, if you begin on theSYSTEM folder page 2, change to the INFO folder andreturn to the SYSTEM folder, page 2 will be the pagedisplayed.

3/3

SYSTEM SETTINGSINFO

Loaded RemoteLoad Selected

Power On Hours 12338Running Hours 11445Loaded Hours 11223

BCM Ver: 2.51

Number of Starts 35

1/3

SYSTEM SETTINGSINFO


START LOAD UNLOAD

RESET

HORN SILENCECONTRAST

LEFTUPRIGHT

DOWN

ENTER

STOP

1/6

SYSTEM SETTINGSINFO


Password * * * * Setpoint Changes Enabled

English degF mils amps psiLanguage and Units

Date, yyyy/mm/dd 1999/08/31Time, hh:mm:ss 12:30:00

English degC mils amps kg/cm2

2/6

SYSTEM SETTINGSINFO


MaxLoad (HLL) 400.0

User Setpoint (TL) 100.0

Surge Index Increment 1.0 Control Setpoint 100.0

Surge Absorber EnabledSurge Sensitivity 9.0

MinLoad

6/6

SYSTEM SETTINGSINFO


Alarm TripStage 1 Temperature 120 125Stage 1 Vibration 0.80 1.00Stage 2 Temperature 120 125Stage 2 Vibration 0.75 0.95Oil Pressure 18 16High Oil Temperature 120 125Low Oil Temperature 100 95

4/6

SYSTEM SETTINGSINFO


Modulate Autodual Reload Pressure, % of Setpoint 98 Unload Point, BV % Open 1 Unload Delay Time, seconds 1

ManualControl Mode

5/6

SYSTEM SETTINGSINFO


Starting Timer, seconds 20

CT Ratio 60 Motor Failure Trip Enable

Coasting Timer, seconds 240

Setpoint Ramp Rate, pressure/scan 5.0Inlet Unload Position, % 15.0

3/6

SYSTEM


PB IT D

Pressure 10.0 0.5 0.0

Pressure 10.0 0.5 0.0

MinLoad (TL) 25.0 0.5 0.0 MaxLoad (HLL) 100.0 0.5 0.0

SETTINGSINFO

Inlet Valve

Bypass Valve

rep/sec sec

2/3

SYSTEM SETTINGSINFO

Not Ready RemoteTrip

Event Name Time Date 1 Low Oil Pressure Trip 09:18:44 0720 2 Low Oil Pressure Alarm 09:18:43 0720 3 Reset key pressed 09:18:34 0720 4 Low Oil Pressure Trip 09:08:43 0720 5 Low Oil Pressure Alarm 08:58:23 0720 6 Load key pressed 08:24:01 0720 7 Start key pressed 08:23:12 0720

SYSTEM Folder

4/4

SETTINGSINFOSYSTEM

Digital Outputs


Prelube Pump RunningCR1Remote Trouble

3/4

SETTINGSINFOSYSTEM

Digital Inputs


Starter FeedbackE-Stop PressedLow Seal Air

2/4

SETTINGSINFOSYSTEM

Press Temp Vib


Stage 1 30.1 95.8 0.25Stage 2 106.6 93.5 0.22Oil 20.3 105.5

1/4

SETTINGSINFOSYSTEM

MotorCurrent

SystemPressure

PressureSetpoint

105.1105.0323.4

Loaded

InletValveBypassValve

1000

RemoteLoad Selected

31-AUG-1999 12:00:00Running Hours: 11445



25

1/4

SETTINGSINFOSYSTEM

MotorCurrent

SystemPressure

PressureSetpoint

105.1105.0323.4

Loaded

InletValveBypassValve

1000

RemoteLoad Selected

31-AUG-1999 12:00:00Running Hours: 11445

System Folder – Page 1: System Pressure

2/4

SETTINGSINFOSYSTEM

Press Temp Vib


Stage 1 30.1 95.8 0.25Stage 2 106.6 93.5 0.22Oil 20.3 105.5

3/4

SETTINGSINFOSYSTEM

Digital Inputs


Starter FeedbackE-Stop PressedLow Seal Air

System Folder - Pages 2,3: Analog/Digital Inputs

SYSTEM FolderThe SYSTEM folder provides information about the compressor system. The number ofpages in this folder is at least four; but could be more for two stage machines with special

analog options purchased, or forcompressors with three stages ormore.

This page shows the maincompressor operating parameters,running hours, date and time. TheSystem Pressure and PressureSetpoint are in units as defined bythe Settings page, Motor Current isin Amps and valve positions are inpercent open. Pressure Setpoint isalways editable while the Inlet andBypass Valve positions are edit

enabled when in the Manual mode only. These are the only editable settings in any folderother than the Settings Folder.

Info Folder Page 1 Edit Parameters Table

Variable UnitsMinimum

ValueMaximu

mValue

StepSize

Pressure Setpoint pressure 0.0 999.9 0.1

Inlet Valve Position (manual mode only) percent 0 100 1

Bypass Valve Position (manual mode only) percent 0 100 1

The Analog Input page provides theactual value for each stage pressure,temperature and vibration, oil pressureand temperature. If additional analoginputs have been purchased or morestages exist as standard, it is likely thatan additional page or pages will beadded. The units are as defined by theSettings page. There are nochangeable setpoints on this page.

The Digital Input page shows thecurrent state of the digital (discrete)inputs for the system. The number ofinputs will vary depending upon thenumber of optional inputs purchased. Acheck in the box to the left of the textindicates a TRUE condition, whereas,no check indicates a FALSE condition.For example, a check mark in the “E-Stop Pressed” boxed means that theEmergency Stop push button has been




4/4

SETTINGSINFOSYSTEM

Digital Outputs


Prelube Pump RunningCR1Remote Trouble

System Folder - Page 4: Digital Outputs

2/3

SYSTEM SETTINGSINFO



Info Folder - Page 2: Scrollable Event Log

pressed. It is possible to have multiple Digital Input pages.

The Digital Output page is similarto the Digital Input page except thatit shows the current state of thedigital (discrete) outputs for thesystem. The number of outputs willvary depending upon the number ofoptional items purchased. A checkin the box to the left of the textindicates a TRUE condition,whereas, no check indicates aFALSE condition. It is possible tohave multiple Digital Output pages.

The SYSTEM folder’s four pagesgive the current operating status for the compressor. The User is always within twokeystrokes of all operating parameters.

INFO FolderThe INFO folder contains the OUI key map, the compressor event log and the hour meters.There are no changeable setpoints in this folder. The OUI key map will be the default pageon power up. The keys are labeled in English and the local language, depending upon thecurrent language selected.

The Event Log details the lasttwo-hundred twenty four (224)“events” that have occurred.Each “event” has a date and timestamp. This log for all Alarmsand Trips satisfies first-outindication. Any time an Alarm orTrip is indicated on the StatusBar, the detail for that fault isincluded here.

The event labeled as “1” is thenewest event and “7” is theoldest event. For events that have identical Time and Date values, the order is still correct(newest to oldest, top to bottom). Once the list is full, each new event knocks off the lastevent.

Pressing the Enter key to initiate Scroll Mode allows access to events 17 through 224. ScrollMode is indicated by the reverse video of the event numbers. Each Down Arrow pressdisplays the next seven events. An Up Arrow press will display the previous seven events.Any time a Trip occurs, the system will send the display to the first seven events.



27

Possible Events List

Event Name Description

* * End of List * * Displayed for the event name whenever the event list is not full.

A/I Alarm The actual value for Analog Input “AI” is greater than the Alarm value.

A/I Trip The actual value for Analog Input “AI” is greater than the Trip value.

Acknowledge (Location) An Acknowledge command has been issued from Location.

Auto Start An automatic start occurred (typically from Auto Hot or Cold Start).

Auto Stop An automatic stop occurred (typically from Running Unloaded Shutdown Timer).

BCM 2 Failure Alarm Communications have been lost to Base Control Module #2.

BCM 3 Failure Alarm Communications have been lost to Base Control Module #3.

Compressor Started The compressor has started.

DI Alarm The Discrete Input “DI” is in an alarm condition.

Discrete Surge A discrete surge switch has detected a surge.

DI Trip The Discrete Input “DI” is in a trip condition.

Edit-x AI Alarm SP The Analog Input “AI” Alarm setpoint value has been edited from location x.

Edit-x AI Trip SP The Analog Input “AI” Trip setpoint value has been edited from location x.

Edit-x A/D Reload Pct The AutoDual Reload Percent value has been edited from location x.

Edit-x A/D Unload Dly The value has been edited from location x.

Edit-x A/D Unload Pt The AutoDual Unload Point value has been edited from location x.

Edit-x AHS Pressure The Auto Hot Start Pressure value has been edited from location x.

Edit-x Auto Stop Time The Auto Stop Timer value has been edited from location x.

Edit-x BV Position The Bypass Valve Position value has been edited while in Manual from location x.

Edit-x BV-PID D The Bypass Valve Pressure PID Derivative value has been edited from location x.

Edit-x BV-PID It The Bypass Valve Pressure PID Integral Time value has been edited from location x.

Edit-x BV-PID Pb The Bypass Valve Pressure PID Proportional Band value has been edited from location x.

Edit-x Coasting Timer The Coasting Timer value has been edited from location x.

Edit-x CT Ratio The CT Ratio value has been edited from location x.

Edit-x Day The Day value for the Date field has been edited from location x.

Edit-x IV Position The Inlet Valve Position value when in Manual has been edited from location x.

Edit-x IV Unload Pos The Inlet Valve Unload Position value has been edited from location x.

Edit-x IV-PID D The Inlet Valve Pressure PID Derivative value has been edited from location x.

Edit-x IV-PID It The Inlet Valve Pressure PID Integral Time value has been edited from location x.

Edit-x IV-PID Pb The Inlet Valve Pressure PID Proportional Band value has been edited from location x.

Edit-x MaxLoad SP The MaxLoad Setpoint value has been edited from location x.

Edit-x MaxLoad-PID D The Inlet Valve MaxLoad PID Derivative value has been edited from location x.

Edit-x MaxLoad-PID It The Inlet Valve MaxLoad PID Integral Time value has been edited from location x.

Edit-x MaxLoad-PID Pb The Inlet Valve MaxLoad PID Proportional Band value has been edited from location x.

Edit-x MinLoad Index The MinLoad Surge Index Increment value has been edited from location x.

Edit-x MinLoad SP The MinLoad Setpoint value has been edited from location x.

Edit-x MinLoad-PID D The Bypass Valve Pressure PID Derivative value has been edited from location x.

Edit-x MinLoad-PID It The Bypass Valve Pressure PID Integral Time value has been edited from location x.

Edit-x MinLoad-PID Pb The Bypass Valve Pressure PID Proportional Band value has been edited from location x.

Edit-x Month The Month value for the Date field has been edited from location x.

Edit-x PSP Ramp Rate The Pressure Setpoint Ramp Rate value has been edited from location x.

Edit-x Sensitivity The Surge Sensitivity value has been edited from location x.

Edit-x Starting Timer The Starting Timer value has been edited from location x.

Edit-x Sys Press SP The System Pressure Setpoint value has been edited from location x.




3/3

SYSTEM SETTINGSINFO


Power On Hours 12338Running Hours 11445Loaded Hours 11223

BCM Ver: 2.52

Number of Starts 35

Info Folder - Page 3: Hour Meters and Version

Edit-x Time The Time value has been edited from location x.

Edit-x Year The Year value for the Date field has been edited from location x.

E-Stop pressed Emergency Stop push button has been pressed.

Load (Location) A Load command has been issued from network communications.

Loss of Motor Current Motor current feedback was lost while running.

MinLoad Clamped The MinLoad Control or User Setpoint value has been limited to the MaxLoad Setpoint value.

MinLoad Incremented The MinLoad Control Setpoint value has been incremented as a result of surge.

MinLoad Reset The MinLoad Control Setpoint value has been reset to the MinLoad User Setpoint value.

Starting Fail Driver feedback was not received after a Start command was issued.

Starter Failure Feedback was not received from the starter after a Start command was issued.

Power Down The Base Control Module (BCM) was de-energized.

Power Up The Base Control Module (BCM) was energized.

Reset (Location) A Reset command has been issued from Location.

Start (Location) A Start command has been issued from Location.

Starter Failure Starter feedback was not received after a Start command was issued.

Stop (Location) A Stop command has been issued from Location.

Surge The controller has detected a Surge.

Surge Unload Alarm The alarm condition when the compressor has unloaded as a result of multiple surges.

Unload (Location) An Unload command has been issued from Location.

NOTE 1: “Location” is replaced by “Comm” for communications network, “Local” for local compressor display and “Remote”for hardwired remote communications.NOTE 2: “x” is replaced by “C” for edits from a communication network and “L” for edits from the local display.NOTE 3: All Analog Inputs get edit local, edit communications, alarm and trip event messages.NOTE 4: All Discrete Inputs for Alarm or Trip get alarm and trip event messages.

This last INFO Folder pageshows the hour meters andnumber of starts. Power OnHours is the time that the panelpower has been on. The RunningHours is the amount of time thatthe compressor has beenoperating between each start andstop sequence. The LoadedHours is the amount of time thatthe compressor has been runningand not running unloaded. It canalso be defined as the number ofhours that the inlet valve is not inthe Inlet Unload Position. The Number of (Compressor) Starts is self-explanatory.

NOTE

Most electric motors are only rated for two cold starts or one hot start per hour. It isthe operator’s responsibility not to exceed the electric motor’s limitation. The controlsystem allows the compressor to be started when the compressor is ready, not themotor.



29

1/6

SYSTEM SETTINGSINFO


Password * * * * Setpoint Changes Enabled

English degF mils amps psiLanguage and Units

Date, yyyy/mm/dd 1999/08/31Time, hh:mm:ss 12:30:00

English degC mils amps kg/cm2

Settings Folder - Page 1: Password, Language, Timeand Date

The last item on this page is the Base Control Module Version number. This will be used byfield personnel for quick reference to determine if newer software is available.

SETTINGS FolderThe SETTINGS folder is used for compressor setup. In this folder, the User will enterperformance and control operating parameters, analog health monitoring settings for Alarmand Trip conditions, control mode selection, setpoint changes, password, and user interfacelanguage. This folder is the primary location for editing setpoints.

The Password is used for determiningwhether Setpoint Changes can bemade. The Password takes fournumbers. If the Password is enteredproperly, Changes will be enabled (acheck will be in the box); otherwise,they are disabled. This enabling anddisabling applies to all changeablesetpoints except, Pressure Setpoint,Throttle Limit, language selection andthe Password, these items are alwaysmodifiable.

Each control system is shipped withtwo languages and units of measurecombinations. The first set is for the English language, pressures in units of PSIG,temperatures in units of degrees F and vibrations in units of mils. The other set will belocalized for the customer. The default alternate language is English with Metric units.Language support will be provided as standard for English, all European languages requiredfor the CE Mark, and Chinese. Others will be available as required and translations can beobtained. This system has the ability for any language because of the graphics display.Asian character support will require additional screens because these characters requirefour times the number of pixels. There are no limitations on the units of measure. Eachanalog input has its own scaling factor and offset.

The Date is set with three separate values (1) Year, including century (2) Month and (3) Day.The Time is also set with three values (1) Hour, (2) Minutes and (3) Seconds.

Settings Folder Page 1 Edit Parameters Table


ValueMaximu

mValue

StepSize

Password Digit dimensionless 0 9 1

Date (Year) years 1990 2089 1

Date (Month) months 1 12 1

Date (Day) days 1 31 1

Time (Hour) hours 0 23 1

Time (Minute) minutes 0 59 1

Time (Second) seconds 0 59 1




2/6

SYSTEM SETTINGSINFO


MaxLoad (HLL), amps 400.0

User Setpoint (TL), amps 100.0

Surge Index Increment, amps 1.0 Control Setpoint, amps 100.0

Surge Absorber EnabledSurge Sensitivity 9.0

MinLoad

Settings Folder - Page 2: Anti-Surge and Driver Over-Load Protection

The Anti-surge Settings and Driver Over-Load Protection Page has all of the settings forcontrolling and detecting surge conditions and protecting the main driver from over loadconditions.

The MaxLoad (HLL) setpointprevents the compressor driverfrom overloading. MinLoad UserSetpoint (TL) is the value used todetermine what the initial value(before indexing) when the bypassvalve begins constant pressurecontrol in lieu of the inlet valve.MinLoad Control Setpoint is theactual value used to determinewhen the bypass valve beginsconstant pressure control in lieu ofthe inlet valve. This value equals theMinLoad User Setpoint plus thenumber of surges times the index

increment value. MinLoad Surge Index Increment is the value that the Control Setpoint isindexed after a surge has been detected. If the value for Surge Index Increment is equal tozero, Surge Indexing is disabled.

To reset the MinLoad Control Setpoint to the MinLoad User Setpoint, hold the reset key for atleast five seconds. The indication that it has been reset will be in the event log. The eventmessage “MinLoad Reset” will be displayed. Another indication is when the MinLoad UserSetpoint value equals the MinLoad Control Setpoint value.

The Surge Absorber Enabled checkbox allows the user to turn off or on the Surge Absorberfeature. When disabled, the compressor will Unload on any surge condition.

The Surge Sensitivity setting has a range from one (1) to ten (10) where one is not sensitive(a “soft” surge condition could exist without being identified) and ten is very sensitive (a“soft” surge condition would be identified). We ship the machine with a default value of nine(9). This setting will pick up most surge conditions.



ValueMaximu

mValue

StepSize

MaxLoad (HLL) amps 0.0 9999.9 0.1

MinLoad User Setpoint (TL) amps 0.0 MaxLoad 0.1

MinLoad Surge Index Increment amps 0.0 9999.9 0.1

Surge Sensitivity dimensionless 0.0 10.9 0.1

NOTE

MinLoad Control Setpoint is the power value used to determine when the bypass valveopens. MinLoad Control Setpoint will always be equal to or greater than the ThrottleLimit value.



31

3/6

SYSTEM


PB IT D

Pressure 10.0 0.50 0.00

Pressure 10.0 0.50 0.00

MinLoad (TL) 25.00 0.50 0.00 MaxLoad (HLL) 99.99 0.50 0.00

SETTINGSINFO

Inlet Valve

Bypass Valve

rep/sec sec

Settings Folder - Page 3: Control Parameters (PIDSettings)

CAUTION

The MaxLoad (HLL) value should not exceed the value determined in thesection titled Setting MaxLoad. Failure to set this properly could result in damage tothe motor.

CAUTION

When Surge Indexing is enabled and the compressor surges several times,the compressor will begin bypassing air sooner than when Surge Indexing is disabled.You should periodically reset the MinLoad Control Setpoint to prevent excessive airbypass.

CAUTION

Repeated surging can cause damage to the compressor; therefore, usecaution when desensitizing the Surge Sensitivity setting.

The Control Parameters Page isused for matching the controlsystem to the local application.The Proportional Band (PB),Integral Time (IT) and Derivative(D) settings are provided for boththe inlet valve and bypass valves.This gives the controller precisecontrol for modeling the airsystem over the entire operatingrange of the compressor. Withthis release, the Derivativeconstant has been added to giveeven more capability to match thecontrol system to the air system. However, we recommend that this value remain at zerounless you have full understanding of how this parameter works.



ValueMaximu

mValue

StepSize

Each PB (Proportional Band) dimensionless 0.0 99.99 0.1




4/6

SYSTEM SETTINGSINFO


Modulate Autodual Reload Pressure, % of Setpoint 98 Unload Point, BV % Open 1 Unload Delay Timer, seconds 1

ManualControl Mode

Settings Folder - Page 4: Control Mode Selection

Each It (Proportional Band) repeats/second 0.0 99.99 0.1

Each D (Proportional Band) seconds 0.0 99.99 0.1

CAUTION

Setting the Derivative parameter to a value other than zero for any of the PIDsettings may cause the valve output to change rapidly. Please change this value withcaution.

The Control Mode Selection Pageallows the User to select betweenthe two standard control modes,Modulate and Autodual. Thisselection process is performedwith the radio button selector. Tochange the selection, press theUp or Down arrow key.

Reload Percent, Unload Point andUnload Delay Time are allsetpoints for Autodual control.

Checking the Manual checkboxenables manual valve control. In this mode, the inlet valve may be stroked when thecompressor is not running, and the bypass valve can be stroked at any time. If a surgecondition occurs while manually controlling these valves, the CMC will automatically takeover the valves.



ValueMaximu

mValue

StepSize

Autodual Reload Pressure % of Setpoint 0 99 1

Autodual Unload Point BV % Open 1 99 1

Autodual Unload Delay Timer seconds 0 999 1

CAUTION

Manual should only be used for compressor setup.

Starting Timer is the length of time prior to enabling the loading of the compressor. Typically,this time includes the starter transition time (Y-D time). When this timer expires, the prelubepump will turn off and the compressor is enabled for loading.



33

5/6

SYSTEM SETTINGSINFO


Starting Timer, seconds 20

CT Ratio 60 Motor Failure Trip Enable

Coasting Timer, seconds 240

Setpoint Ramp Rate, pressure/scan 5.0Inlet Valve Unload Position, % 15

Settings Folder - Page 5: Miscellaneous

6/6

SYSTEM SETTINGSINFO


Alarm TripStage 1 Temperature 120 125Stage 1 Vibration 0.80 1.00Stage 2 Temperature 120 125Stage 2 Vibration 0.75 0.95Oil Pressure 18 16High Oil Temperature 120 125Low Oil Temperature 100 95

Settings Folder - Page 6: Alarm and Trip

Coasting Timer is the length of time that it takes for the driver to stop rotating.

CT Ratio is the ratio of the currenttransformer primary to thesecondary; i.e., if the CT primarywinding is 300 and the secondarywinding is 5, then the CT Ratio is60.

When checked, Motor Failure TripEnable tests that the zero ampmotor current has been reachedafter a start command has beeninitiated and that motor current isnot lost while the compressor isrunning. Uncheck this box for dry

run conditions.

The Inlet Unload Position is the position of the inlet valve when in the unload state.

Setpoint Ramp Rate is used to prevent system pressure overshoot during compressorloading.

Additional settings will be added to this page for “special” features.



ValueMaximu

mValue

StepSize

Starting Timer seconds 5 60 1

Coasting Timer seconds 0 9999 1

CT Ratio dimensionless 60 9999 1

Inlet Valve Unload Position percent 0 100 1

Setpoint Ramp Rate pressure/scan 0 999.9 0.1

WARNING

Failure to set the Coast Timer for a period greater than or equal to the actualcoasting time can result in compressor damage.

The Alarm and Trip Settings Pageprovides the means for changingthe analog health monitoringvalues. The number of inputsvaries depending upon the numberof compression stages andoptional inputs. Additional pageswill be added as needed after this




page. All line items are changeable for the Alarm and Trip setpoints.

General Sequence of Operation


1/2

SETTINGSINFO

MotorCurrent

SystemPressure

PressureSetpoint

105.3105.0173.4

Loaded

InletValve

BypassValve

950

RemoteLoad Selected

22JUL96 12:00:00

SYSTEM

1 PressReset

2 Look for"Ready"

To start and load acompressor followsteps 1, 2, 3 and 4

Press Stop

Press Unload,wait 20 seconds5

6

To unload and stopa compressor follow

steps 5 and 6

Press Start3

4 Press Load

Un

load

ed

Co

asti

ng

Sta

rtin

g

Lo

adin

g

Lo

aded

Min

Lo

ad

Fu

ll L

oad

Lo

aded

Max

Lo

ad

Un

load

ing

Un

load

ed

RotatingStopped

Not

Rea

dy

Rea

dy

Wai

ting

100

0

MotorCurrent

amps, %

NoStops or

Trips Start

Zero Amp Offset

Unloaded Amps

Motor Full Load Amps

Motor Full Load Amps Plus Service Factor

AnyStops or

Trips

Unload

MinLoad Setpoint AmpsLoad

MaxLoad Setpoint Amps

PowerOn

Compressor Operating Statesfor Motor Driven Packages



35

Indicator, Switch and Light LayoutIn addition to the CMC OUI there may be a variety of indicators, switches, and lightsmounted on the control panel door. In conjunction with the CMC OUI these devices make upthe User Interface for the CMC. A typical device layout consists of the following lights, pushbuttons, and selector switches.

LightsThe lights provided are the green CONTROL POWER ON light, which is integral to theCONTROL POWER OFF/ON switch, the amber PRELUBE PUMP RUNNING light and thered TROUBLE INDICATION light.

Push ButtonsThe red EMERGENCY STOP push button stops the compressor any time that it is pressed.This push button is used to initiate a stop in the case of an emergency.

SwitchesThe CONTROL POWER OFF/ON selector switch turns the panel power on or off

CMC Tuning ProceduresWhen commissioning a new compressor, troubleshooting an existing compressor, or tuninga system, the following procedures may be required. The procedures are performed, andany changes required are made through the CMC OUI. For instructions on how to use theOUI refer to the section titled User Interface. The following figure will be referenced in theprocedures.

CompressorMotor

StarterCT

BypassValve

InletValve

CheckValveBase

ControlModule

PT1

4-20 mA

4-20 mA

PT2

Pneumatic Tubing

Plant Air System

Inlet Filter

BlockValve

Figure 11: Plant Air System




Setting MaxLoadThe MaxLoad Setpoint keeps the motor within the allowable current range. To determine thevalue for MaxLoad, an Adjusted Service Factor (ASF) is multiplied by the motor full loadamps (FLA). The (ASF) is found by obtaining the motor service factor from the motornameplate and selecting the adjustment factor from the table below. The motor full loadamps is found on the motor nameplate.

Motor Service Factor Adjusted Service Factor1.15 1.051.25 1.10

Example: MaxLoad = FLA X ASFFLA: 134 Amps

Motor service factor: 1.15MaxLoad: 140

Setting MinLoadMinLoad establishes the minimum flow through the machine when loaded, it is themaximum point of inlet valve throttling. If system demand is below this throttle point, thecompressor must bypass air or unload. If flow were allowed to go below MinLoad, themachine would eventually hit the surge line and surge. By stopping inlet valve throttling atMinLoad the machine is kept out of surge. To find the MinLoad setting, the machine is runinto the surge line, and the value of load (amps, kilowatts, SCFM) at surge is recorded. Therecorded value is then incremented by five percent and set as the value for MinLoad.

1. Before continuing this procedure, verify the following:

a) The inlet and bypass control valves have been calibrated.

b) The machine is running unloaded.

c) The block valve at the inlet to the plant air system (Figure 11) is closed.

d) The pressure setpoint is set to the pressure at which the machine is going tooperate.

2. Set initial MinLoad estimates.

a) In the Settings Folder, select the Edit Data cell for MinLoad.

b) Increment or decrement the value to achieve a value of approximately 95% of fullload amps.

3. Preset the manual bypass valve position to 100.

a) On the OUI select the Settings Folder and enable manual valve control byhighlighting the manual check box.

NOTE

When Manual is enabled, both control valves can be positioned while stopped, whileonly the Bypass Valve can be positioned when Loaded.



37

b) Switch to the System Folder Page 1 and press the Enter Key to enable edit mode.

c) Use the horizontal navigation keys to select the bypass valve.

d) Increment the value to position the valve to 100 percent.

4. Load the compressor by pressing the Load Key.

5. Find the throttled surge point.

a) Slowly decrement the bypass valve position until the last stage discharge pressureequals the pressure setpoint.

b) Allow the system to stabilize at MinLoad. It the system does not stay at MinLoad,slightly decrement the valve position to force the machine to throttle to MinLoad.

c) Decrement (MinLoad) 2%.

d) Verify the last stage pressure equals the pressure setpoint and adjust the bypassvalve position if necessary.

e) Repeat 5.2-4 until the compressor surges.

6. Increase MinLoad by five percent.

7. Exit MinLoad editing by pressing the Enter Key.

8. Unload the machine.

9. Disable manual valve control by unchecking the manual check box.

Setting MinLoad Surge Index IncrementWhen Surge Indexing is enabled (MinLoad Surge Index Increment is greater than zero), theIndex Increment value is the amount added to the MinLoad Control Setpoint upon a surge.The MinLoad Control Setpoint will stop being incremented when and if the value reachesMaxLoad.

Setting Surge SensitivityThe Surge Sensitivity setting should be set sensitive enough to detect a surge, yet nottrigger on spurious noise in the system. To set the surge sensor the machine is forced tosurge by running the machine at MinLoad and the MinLoad setpoint is dropped until themachine audibly surges. The process is repeated until the correct setting is found.

1. Before continuing this procedure, verify the following:

a) The plant can tolerate a pressure disturbance when the machine surges.

b) Surge Indexing (by placing MinLoad Surge Index Increment to zero) is disabled.

c) Surge Absorber is disabled.

d) The pressure setpoint is set to the pressure at which the machine is going tooperate.

e) The machine is running unloaded.

2. Set the initial Surge Sensitivity setting to 9.

a) In the Settings Folder, select the Edit Data cell for Surge Sensitivity.




b) Increment or decrement the value to achieve a setting of 9.

3. Press the Load Key.

4. Run the compressor at MinLoad at pressure. The machine can be forced to MinLoadand pressure by either:

a) Running the plant at a higher pressure than pressure setpoint.

b) Decreasing load in the plant.

c) Verify the compressor is at pressure by observing the last stage pressure onPage 2 of the Settings Folder.

5. Find the throttled surge point.

a) Select the MinLoad cell in the Settings Folder and slowly decrement the value untilthe machine surges. Typically the machine will make a puffing or popping noiseupon surge, this is your indication surge has occurred.

6. Press the Unload Key.

7. Determine if Surge was recorded.

a) Inspect the Status Bar. If the message Surge Unload is displayed surge wasrecorded, if the message is not displayed surge was not recorded.

8. Check the Surge Sensitivity setting.

a) If the surge was recorded, the setting may be correct or the Surge Sensor may betoo sensitive, skip to the too sensitive step, which follows.

b) If the surge was not recorded, the setting is not sensitive enough, skip to the notsensitive enough step which follows.

9. Surge Sensor too sensitive.

a) Select the Surge Sensitivity Setting in the Settings Folder.

b) Decrease the value for Surge Sensitivity by 0.1.

c) Press the Reset Key.

d) Skip to step 11.

10. Surge Sensor not sensitive enough.

a) Select the Surge Sensitivity Setting in the Settings Folder.

b) Increase the value for Surge Sensitivity by 0.1.

c) Press the Reset Key.

11. Repeat the procedure until the Surge Sensitivity setting is found which just catches asurge but does not miss a surge.

a) Return to step 3.

12. Restore all values but Surge Sensitivity.

Tuning StabilityThe CMC controls stability with four Proportion Integral Derivative (PID) control loops. Whenthe machine is running above the MinLoad point and below the MaxLoad point, pressure is



39

regulated with the Inlet Valve Pressure control loop. When the machine is running at theMinLoad point, pressure is regulated with the Bypass Valve Pressure control loop and motorcurrent is regulated with the Inlet Valve MinLoad control loop. When the machine is runningat MaxLoad motor current is regulated with the Inlet Valve MaxLoad control loop. For eachPID loop, Proportional, Integral and Derivative parameters are used to stabilize the system.For a definition of the parameters and their effect on stability, refer to the section titled “Howdoes Constant Pressure Modulation Work.” The proportional and integral terms are labeledby their respective loops, Inlet Valve, Bypass Valve, MinLoad, and MaxLoad.

Calibrating the Control ValvesThe purpose of this procedure is to position the inlet and bypass valves by opening andclosing each valve from the CMC analog outputs. The valves should be adjusted tophysically correspond with the valve positions displayed on the OUI.

1. Stop the compressor.




NOTE

Performing this procedure while the compressor is operating may cause seriousdamage.

2. On the OUI enable Setpoint changes by entering the password on the Settings Folder.

3. Verify the OUI status bar displays “Ready” or “Not Ready”.

4. On the OUI select the Settings Folder and enable manual valve control by highlightingthe manual check box.

NOTE

When Manual is enabled, both control valves can be positioned while stopped, whileonly the Bypass Valve can be positioned when Loaded.

5. Switch to the System Folder Page 1 and press the Enter Key to enable edit mode.

6. Use the horizontal navigation keys to select the valve requiring positioning.

7. Use the vertical arrows to increment and decrement the valve position sent to the valve.

NOTE

For the Inlet and Bypass Valves, the displayed position corresponds to percent open.

8. Disable manual valve control by blanking the manual check box.

Autodual Control SettingsFor a detailed definition of the Autodual control mode refer to the section titled “ControlMethodology”. The procedure for tuning Autodual requires the setting of the followingvariables:

Unload Point (Bypass Valve % Open)The Bypass Valve Unload Point is selected to correspond to the check valve closing asshown in Figure 11, since at this point the machine is not supplying the system. Thisposition is found by running the machine at MinLoad and monitoring the System andDischarge pressures. When the System pressure is 5% of setpoint greater than the laststage pressure as shown in the System Folder, the check valve is assumed to be closed.



41

Example: Given the following conditions the Unload Point would be set at 35.

Variable Case 1 Case 2Pressure Setpoint 100 100PT1 (system pressure) 100 100PT2 (last stage pressure) 100 94Bypass Valve Position 13 35Assumed check valve position Open Closed

1. Run the machine at MinLoad by elevating the system pressure no more than 3% ordecrease the pressure setpoint no more than 3%.

2. Monitor the difference between the Discharge and System Pressures by using theSystem Folder Pages 1 and 2.

3. When the Discharge Pressure is approximately 5% of setpoint less than the SystemPressure, record the Bypass Valve Position.

4. Enter the recorded Bypass Valve Position as the Unload Point.

Unload Delay Time (seconds)The Unload Delay Timer should be set to prevent unloading during short excursions throughthe Unload Point. Typically, when the check valve closes, system demand requires thecheck valve to open again soon thereafter due to the demand being on the verge of requiringthe compressor. If the compressor had unloaded when the check valve first closed, a reloadwould be immediately required and the machine would go through the automatic unload/loadcycle until demand was consistently low enough to keep the check valve closed. For thisreason, the timer is used to inhibit Unload until demand has consistently remained low.

1. Run the compressor at MinLoad by either:

a) Running the plant at a higher pressure than pressure setpoint.

b) Shedding load in the plant.

2. Determine delay time.

a) Observe time when bypass valve first hits unload point.

b) Observe time when bypass valve remains below unload point, typically less than 300seconds.

c) Enter the time difference as the Delay Time.

Reload PercentThe Reload Percent determines the System Pressure at which the machine willautomatically load into the system. This value should be set according to the customer’sminimum acceptable system pressure.




Setting the Start TimeThe Start Time is set to the transition time of a built-in reduced voltage starter or theacceleration time of a customer supplied starter. This procedure requires the Inlet UnloadPosition to have been set.

1. Initially set the Start Time to 25 Seconds. Caution: Damage to the starter contactscould result if starter transition occurs before the compressor is up to full speed.

2. Stop the compressor.

3. On the OUI record the time and press the start button.

4. Wait for the compressor to stop accelerating and again record the time.

5. Calculate the difference between the two values and enter as the Start Time.

Setting the CT RatioLocate the CT and find the rating, which is typically printed, on the side of the CT. Divide theprimary by the secondary and enter the value as the CT Ratio.

Example: CT is printed with 600:5, the value entered is 120.

Inlet Unload PositionThe purpose of this variable is to set the inlet valve position when the machine is runningunloaded. For a description of the Unloaded state refer to the section titled “Unload”.

1. If the inlet valve is a butterfly type, enter an initial value for Inlet Unload Position of 15. Ifthe inlet valve is a inlet guide vane type, enter an initial value for Inlet Unload Position of5.

2. Start the machine. If during startup the motor trips on overload, is drawing what isconsidered excessive amperage or sounds labored, stop the machine and decrease theUnload Position by 2.

3. Run the machine in the Unloaded state and monitor the first stage pressure.

4. Adjust the Unload Position to achieve 1 PSIG on the first stage discharge, or until apositive pressure is felt at the first stage trap bypass.

5. If the inlet air temperature is relatively cold, increase the setting 2%, this willaccommodate hot day operation.



43

Setting Set Point Ramp RateSetpoint ramp rate determines the rate at which the machine transitions from unloaded toloaded. The setting should be set as high as possible without creating excessive overshootwhen the machine enters the system.

1. Verify the machine is unloaded by the “Unloaded” message in the OUI Status Bar.

2. Determine overshoot.

a) Load the machine.

b) Monitor the pressure overshoot.

3. If overshoot is excessive.

a) Decrease the Setpoint Ramp Rate.

b) Repeat step 2.

4. If overshoot is satisfactory and time to load is excessive.

a) Increase the Setpoint Ramp Rate.

b) Repeat step 2.

5. If overshoot is satisfactory and time to load is satisfactory the Setpoint Ramp Rate iscorrect.

Alarm and Trip SettingsThe values for vibration, temperature, pressure etc. alarm and trip setpoints are located on theelectrical schematic. These values determine when the controller will indicate an alarm or tripcondition.




TroubleshootingThe following procedures provide direction on troubleshooting the CMC System, controlpanel, and associated instrumentation. Faults are either Event Logged, which means thefault is displayed in the INFO Folder on the OUI, or Non-Event Logged. The distinction helpsto expedite the troubleshooting process.

When a control system fault is suspected, the following diagram is used to categorize thefault. The section following the diagram breaks each category down into specific items,which can cause a particular fault.

I/O FAULT

Temperature, pressure, load, valve, etc.readings incorrect.

(Refer to the Input/Output (I/O) System)

COMPRESSOR RELATED

Event correctly indicates a problem.

(Refer to the compressor operating manual)

STABILITY PROBLEMS

Inlet valve, bypass valve, or control variables(mass flow, system pressure, Kw, amps) are

unstable.

(Refer to the CMC Tuning Procedures Section)

CONTROL PROBLEMS

Compressor fails to Load, fails to trip, fails tostart, surging, etc.

(Refer to the CMC Tuning Procedures section)

CONTROLLER PROBLEMS

OUI failed, BCM failed, UCM failed,Communications failed.

(Refer to Controller Problems Section)

A CONTROLSYSTEM FAULT IS

SUSPECTED

THE FAULT IS LOGGED INTHE EVENT LOG.

THE FAULT IS NOT LOGGED INTHE EVENT LOG

Figure 12: Troubleshooting Tree



45

2/3

SYSTEM SETTINGSINFO



Troubleshooting ExampleThe following example will serve as a guide to follow when troubleshooting specificproblems.

Problem Indication:

Plant air pressure is low and the CMC OUI is foundas shown.

Probable Cause Determination:

1. The machine Tripped on Low Oil Pressure, which means the oil pressure, was belowthe Oil Pressure Trip Value. Figure 12 leads to the assumption that the problem iseither compressor or I/O related, because the fault is Event Logged. There are twomost likely causes for this event.

a) Actual oil pressure is low.

i) The prelube pump is found to be running and installation of a calibrated pressuresensor shows the actual oil pressure to be above the Oil Pressure Trip Value.Therefore, the mechanical system is operating correctly.

b) The value read by the CMC is incorrect.

i) The oil pressure value displayed on Page 2 of the System Folder shows the oilpressure to be below the test sensor reading and erratic. Additionally, all otheranalog input readings are normal and not erratic. Therefore, the problem can beisolated to the oil pressure, analog input circuit.

ii) The Pressure Monitoring System (PMS) troubleshooting table, found in thefollowing section “The Pressure Monitoring System” identifies the probablecause for an erratic reading as a loose wire/terminal/connector and specifiesTroubleshooting Procedure PMS #1 and 2 as the appropriate procedures.

Trouble Procedure Execution:

Step 1 of PMS #1 requires disconnecting of the pressure transducer (PT) wires at thetransmitter. When this step is performed, one of the connections is found to be intermittent.When the poor connection is corrected, the erratic reading on the OUI becomes solid.




Input/Output (I/O) SystemVibration Monitoring System (VMS)Description:

The vibration transmitter is used to convert the proximity probe signal into a 4 -20 mA signal,which is monitored by the CMC. The system is based on a 15-foot (4.575 m) total electricallength.

Component specifications:

Transmitter:

• 100 mv/mil = 0.1 volt per 0.001 in (0.0254 mm)

• 4 mil (0.1016 mm) scale

• 4-20 mA output

Probe:

• Gap setting 0.030 to 0.060 in (0.762 to 1.524 mm), 0.050 in (1.27 mm) is nominal gap

• Probe gap corresponds to 3 to 6 volts VDC, 5 VDC nominal

• Probe ohm value 7-12 ohms

Troubleshooting:

The following table identifies typical problems, probable causes, and appropriate proceduresfor verifying the probable cause:

Typical Problem Probable Cause Troubleshooting ProcedureZero OUI readout Open circuit/cable disconnected VMS #2, 3, 4(when compressor is Loss of power to transmitter VMS #1running) Malfunctioning transmitter VMS #2

Transmitter not calibrated VMS #2Erratic OUI readout Loose wire/terminal/connector VMS #2, 3, 4Incorrect OUI readout Any VMS #1, 2, 3, 4, 5



47

Checking Vibration Transmitter Power VMS #1

1. Connect a DC voltmeter to the +and - terminals of thetransmitter.

2. With control power on, thereshould be approximately 24VDC present at the terminals.

3. If approximately 24 VDC is notpresent; see the section titled“Control Power System”.

NOTE: Under no circumstancesshould the vibration transmitter zeroor span be adjusted. Calibration ofthe vibration transmitter requiresspecial tooling and calibrationfixtures. Contact the factory ifcalibration is required.

Vibrationtransmitter

VDC mA

VAC Ω

mA COM V

XXXXX XXXXX XXXXX

XXXXX XXXXX XXXXX

Ω

NON-CONTACT VIBRATIONTRANSMITTER

+

4 TO20 mA

100mV/MIL

COM- TEST

PART NO. 1X9247

S/N XXXXXX

1004

20 mA =

PROBE

INGERSOLL RAND

To BCM J1 Connector(See electricalschematic for point).

Checking Vibration Circuit VMS #2

1. With control power on, check the dcvoltage at the COM and TEST terminalson the transmitter. A reading of 3 to 6VDC should be present [this correspondsto a 0.030 to 0.060 inches (0.762 to 1.524mm)] probe gap.

2. If less than 3 volts is present the probegap may be incorrect, or a short circuitmay exist. Check the cable connectionsand cable.

3. If more than 6 volts is present the probegap may be incorrect, or an open circuitmay exist. Check the cable connectionsand cable.

4. If no voltage exists, the transmitter maybe faulty. Remove control power andswap connections with anothertransmitter and test.

VDC mA

VAC Ω

mA COM V

XXXXX XXXXX XXXXX

XXXXX XXXXX XXXXX

Ω

NON-CONTACT VIBRATIONTRANSMITTER

+

4 TO20 mA

100m V / M I L

COM- TEST

PART NO. 1X9247

S / N XXXXXX

100420 mA =

PROBE

INGERSOLL RANDProbe extension cable

Vibration probe

Compressor casing

Vibration transmitter




Check the Vibration Probe, and Cable VMS #3

1. Turn control power off and disconnect theprobe extension cable from thetransmitter.

2. Check resistance of the extension cableand probe together, the reading should be7 to 20 ohms.

Probe cableVDC mA

VAC Ω

mA COM V

XXXXX XXXXX XXXXX

XXXXX XXXXX XXXXX

Ω

Probe extensioncable

Vibration probe

Compressorcasing

Connect test leadto inner pin.

Connect test leadto outer shell.

Probe connector

Checking the Vibration Probe VMS #4

1. Turn control power off and disconnect theprobe extension cable from thetransmitter.

2. Check resistance of the probe alone, thereading should be 7 to 12 ohms. VDC mA

VAC Ω

mA COM V

XXXXX XXXXX XXXXX

XXXXX XXXXX XXXXX

Ω

Connect test leadto outer shell.

Connect test leadto inner pin.

Vibration probe

Probe cable

Probe connector



49

Check the BCM VMS #5

1. With control power off connect a 4-20 mA simulator at the input points of the suspectedfaulty device at connector J1, (see electrical schematic for connection points).

2. Turn control power on and vary the signal. If the value tracks according to the tablebelow, the wiring is faulty.

3. Verify the connector at J1 is fully seated. If the value does not track correctly, the BCMmay be faulty.

J2-Floating Analog Inputs, (4-20mA) Channels 1-2

J1-Grounded Analog Inputs,(4-20mA) Channels 3-23

Pin 1

Pin 25m

A O

UT

2 WIR

E

OFF

100%

00.0%

DIA

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CK

LOO

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XX

XX

XX

MO

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L-X

XX

00.0% - 100%

55

5

4-20 mA SURCE OR2 WIRE SIMULATOR

BCM

Conversion chartmA percent

(from simulator)Mils

(on OUI)mA

(from simulator)100% 4.0 2050% 2.0 120% 0.0 4




Temperature Monitoring System (TMS)Description:

An RTD (Resistance Temperature Detector-2 Wire) with external transmitter is used by theCMC for temperature monitoring. An RTD resistance (ohmic value) varies with temperature.A transmitter for monitoring by the CMC analog input channel converts the resistance to a 4-20 mA signal.

Component specification:

Probe:

• 100 ohm Platinum resistance at 32 °F (0°C). Two types are used:

Transmitter:

• The transmitter may be mounted in the RTD connection head fitting or in the controlpanel enclosure. The transmitter is supplied 24 VDC and outputs 4-20mA over a fixedrange of either 0 to 200°F (-17.7 to +93.3°C) , or 0-500°F (-17.7 to +260°C).

Troubleshooting:


Typical Problem Probable Cause TroubleshootingProcedure

High OUI readout High resistance connection TMS #4Transmitter not calibrated TMS #3RTD failure TMS #2Transmitter failure TMS #3

Low OUI readout Transmitter failure TMS #3RTD failure TMS #2Transmitter not calibrated TMS #3

Erratic OUI readout Loose terminal connection TMS #4RTD internal wire fault TMS #2Transmitter failure TMS #3

Incorrect OUI readout Transmitter not calibrated TMS #3RTD or transmitter failure TMS #2, 3Any TMS #1, 2, 3, 4



51

Checking for Power to the Temperature Transmitter TMS #1

1. Disconnect the wires at terminals #1 and #2 on the transmitter and connect a voltmeterto these wires.

2. With control power on, there should be approximately 24 VDC present at the terminals.3. If approximately 24 VDC is not present, see the section titled “Control Power System”.

1 2 3 4

Temperature transmitterRTD



Pin 1

Pin 25

BCM

VDC mA

VAC Ω

mA COM V

XXXXX XXXXX XXXXX

XXXXX XXXXX XXXXX

Ω




Checking for a Faulty RTD TMS #2

1. Turn control power off.2. Check ohms versus temperature. Use an

Ohmmeter and the following tables todetermine if the RTD is faulty. Vary thetemperature to the RTD and check theohms around the normal operating range.

ThermometerRTD

32 DEGF

Ice water

VDC mA

VAC Ω

mA COM V

XXXXX XXXXX XXXXX

XXXXX XXXXX XXXXX

Ω



53

Degrees Fahrenheit versus Ohms value chart for 100 OHM Platinum RTD°F 0 1 2 3 4 5 6 7 8 9

0 93.01 93.22 93.44 93.66 93.88 94.10 94.32 94.54 94.76 94.9810 95.20 95.42 95.63 95.85 96.07 96.29 96.51 96.73 96.95 97.1720 97.38 97.60 97.82 98.04 98.26 98.47 98.69 98.91 99.13 99.3530 99.56 99.78 100.00 100.20 100.40 100.70 100.90 101.10 101.30 101.5040 101.70 102.00 102.20 102.40 102.60 102.80 103.00 103.30 103.50 103.7050 103.90 104.10 104.30 104.60 104.80 105.00 105.20 105.40 105.60 105.8060 106.10 106.30 106.50 106.70 106.90 107.10 107.40 107.60 107.80 108.0070 108.20 108.40 108.70 108.90 109.10 109.30 109.50 109.70 109.90 110.2080 110.40 110.60 110.80 111.00 111.20 111.50 111.70 111.90 112.10 112.3090 112.50 112.70 113.00 113.20 113.40 113.60 113.80 114.00 114.30 114.50

100 114.70 114.90 115.10 115.30 115.50 115.80 116.00 116.20 116.40 116.60110 116.80 117.00 117.30 117.50 117.70 117.90 118.10 118.30 118.50 118.80120 119.00 119.20 119.40 119.60 119.80 120.00 120.20 120.50 120.70 120.90130 121.10 121.30 121.50 121.70 122.00 122.20 122.40 122.60 122.80 123.00140 123.20 123.40 123.60 123.90 124.10 124.30 124.50 124.70 124.90 125.20150 125.40 125.60 125.80 126.00 126.20 126.40 126.60 126.90 127.10 127.30160 127.50 127.70 127.90 128.10 128.30 128.60 128.80 129.00 129.20 129.40170 129.60 129.80 130.00 130.30 130.50 130.70 130.90 131.10 131.30 131.50180 131.70 132.00 132.20 132.40 132.60 132.80 133.00 133.20 133.40 133.60190 133.90 134.10 134.30 134.50 134.70 134.90 135.10 135.30 135.50 135.80200 136.00 136.20 136.40 136.60 136.80 137.00 137.20 137.40 137.70 137.90210 138.10 138.30 138.50 138.70 138.90 139.10 139.30 139.60 139.80 140.00220 140.20 140.40 140.60 140.80 141.00 141.20 141.40 141.70 141.90 142.10230 142.30 142.50 142.70 142.90 143.10 143.30 143.50 143.80 144.00 144.20240 144.40 144.60 144.80 145.00 145.20 145.40 145.60 145.90 146.10 146.30250 146.50 146.70 146.90 147.10 147.30 147.50 147.70 147.90 148.20 148.40260 148.60 148.80 149.00 149.20 149.40 149.60 149.80 150.00 150.20 150.50270 150.70 150.90 151.10 151.30 151.50 151.70 151.90 152.10 152.30 152.50280 152.70 153.00 153.20 153.40 153.60 153.80 154.00 154.20 154.40 154.60290 154.80 155.00 155.20 155.40 155.70 155.90 156.10 156.30 156.50 156.70300 156.90 157.10 157.30 157.50 157.70 157.90 158.10 158.40 158.60 158.80310 159.00 159.20 159.40 159.60 159.80 160.00 160.20 160.40 160.60 160.80320 161.00 161.30 161.50 161.70 161.90 162.10 162.30 162.50 162.70 162.90330 163.10 163.30 163.50 163.70 163.90 164.10 164.30 164.60 164.80 165.00340 165.20 165.40 165.60 165.80 166.00 166.20 166.40 166.60 166.80 167.00350 167.20 167.40 167.60 167.80 168.10 168.30 168.50 168.70 168.90 169.10360 169.30 169.50 169.70 169.90 170.10 170.30 170.50 170.70 170.90 171.10370 171.30 171.50 171.80 172.00 172.20 172.40 172.60 172.80 173.00 173.20380 173.40 173.60 173.80 174.00 174.20 174.40 174.60 174.80 175.00 175.20390 175.40 175.60 175.80 176.00 176.30 176.50 176.70 176.90 177.10 177.30400 177.50 177.70 177.90 178.10 178.30 178.50 178.70 178.90 179.10 179.30410 179.50 179.70 179.90 180.10 180.30 180.50 180.70 180.90 181.10 181.30420 181.50 181.80 182.00 182.20 182.40 182.60 182.80 183.00 183.20 183.40430 183.60 183.80 184.00 184.20 184.40 184.60 184.80 185.00 185.20 185.40440 185.60 185.80 186.00 186.20 186.40 186.60 186.80 187.00 187.20 187.40450 187.60 187.80 188.00 188.20 188.40 188.60 188.80 189.00 189.20 189.40460 189.70 189.90 190.10 190.30 190.50 190.70 190.90 191.10 191.30 191.50470 191.70 191.90 192.10 192.30 192.50 192.70 192.90 193.10 193.30 193.50480 193.70 193.90 194.10 194.30 194.50 194.70 194.90 195.10 195.30 195.50490 195.70 195.90 196.10 196.30 196.50 196.70 196.90 197.10 197.30 197.50500 197.70 197.90 198.10 198.30 198.50 198.70 198.90 199.10 199.30 199.50




Degrees Celsius versus Ohms value chart for 100 OHM Platinum RTD°C 0.00 0.62 1.23 1.85 2.47 3.09 3.70 4.32 4.94 5.56

-17.78 93.01 93.22 93.44 93.66 93.88 94.10 94.32 94.54 94.76 94.98-12.22 95.20 95.42 95.63 95.85 96.07 96.29 96.51 96.73 96.95 97.17-6.67 97.38 97.60 97.82 98.04 98.26 98.47 98.69 98.91 99.13 99.35-1.11 99.56 99.78 100.00 100.22 100.43 100.65 100.87 101.08 101.30 101.524.44 101.74 101.95 102.17 102.39 102.60 102.82 103.04 103.25 103.47 103.69

10.00 103.90 104.12 104.34 104.55 104.77 104.98 105.20 105.42 105.63 105.8515.56 106.07 106.28 106.50 106.71 106.93 107.14 107.36 107.58 107.79 108.0121.11 108.22 108.44 108.66 108.87 109.09 109.30 109.52 109.73 109.95 110.1626.67 110.38 110.60 110.81 111.03 111.24 111.46 111.67 111.89 112.10 112.3232.22 112.53 112.75 112.96 113.18 113.39 113.61 113.82 114.04 114.25 114.4737.78 114.68 114.89 115.11 115.32 115.54 115.75 115.97 116.18 116.40 116.6143.33 116.83 117.04 117.25 117.47 117.68 117.90 118.11 118.32 118.54 118.7548.89 118.97 119.18 119.39 119.61 119.82 120.04 120.25 120.46 120.68 120.8954.44 121.11 121.32 121.53 121.75 121.96 122.17 122.39 122.60 122.81 123.0360.00 123.22 123.43 123.65 123.87 124.08 124.30 124.51 124.73 124.94 125.1665.56 125.37 125.58 125.79 126.01 126.22 126.43 126.65 126.86 127.07 127.2871.11 127.50 127.71 127.92 128.13 128.35 128.56 128.77 128.98 129.20 129.4176.67 129.62 129.83 130.04 130.26 130.47 130.68 130.89 131.10 131.32 131.5382.22 131.74 131.95 132.16 132.38 132.59 132.80 133.01 133.22 133.43 133.6587.78 133.86 134.07 134.28 134.49 134.70 134.91 135.12 135.34 135.55 135.7693.33 135.97 136.18 136.39 136.60 136.81 137.02 137.24 137.45 137.66 137.8798.89 138.08 138.29 138.50 138.71 138.92 139.13 139.34 139.55 139.76 139.97

104.44 140.18 140.39 140.60 140.81 141.02 141.24 141.45 141.66 141.87 142.08110.00 142.29 142.50 142.71 142.92 143.13 143.34 143.55 143.76 143.97 144.18115.56 144.39 144.59 144.80 145.01 145.22 145.43 145.64 145.85 146.06 146.27121.11 146.48 146.69 146.90 147.11 147.32 147.53 147.73 147.94 148.15 148.36126.67 148.57 148.78 148.99 149.20 149.41 149.61 149.82 150.03 150.24 150.45132.22 150.66 150.87 151.08 151.28 151.49 151.70 151.91 152.12 152.33 152.54137.78 152.74 152.95 153.16 153.37 153.58 153.78 153.99 154.20 154.41 154.62143.33 154.82 155.03 155.24 155.45 155.66 155.86 156.07 156.28 156.49 156.69148.89 156.90 157.11 157.32 157.52 157.73 157.94 158.15 158.35 158.56 158.77154.44 158.98 159.18 159.39 159.60 159.80 160.01 160.22 160.42 160.63 160.84160.00 161.05 161.25 161.46 161.67 161.87 162.08 162.29 162.49 162.70 162.91165.56 163.11 163.32 163.52 163.73 163.94 164.14 164.35 164.56 164.76 164.97171.11 165.17 165.38 165.59 165.79 166.00 166.20 166.41 166.62 166.82 167.03176.67 167.23 167.44 167.64 167.85 168.06 168.26 168.47 168.67 168.88 169.08182.22 169.29 169.49 169.70 169.90 170.11 170.32 170.52 170.73 170.93 171.14187.78 171.34 171.55 171.75 171.96 172.16 172.37 172.57 172.78 172.98 173.19193.33 173.39 173.59 173.80 174.00 174.21 174.41 174.62 174.82 175.03 175.23198.89 175.44 175.64 175.84 176.05 176.25 176.46 176.66 176.86 177.07 177.27204.44 177.48 177.68 177.88 178.09 178.29 178.49 178.70 178.90 179.11 179.31210.00 179.51 179.72 179.92 180.12 180.33 180.53 180.73 180.94 181.14 181.35215.56 181.55 181.75 181.95 182.16 182.36 182.56 182.77 182.97 183.17 183.38221.11 183.58 183.78 183.98 184.19 184.39 184.59 184.80 185.00 185.20 185.40226.67 185.60 185.81 186.01 186.21 186.41 186.62 186.82 187.02 187.22 187.43232.22 187.63 187.83 188.03 188.24 188.44 188.64 188.84 189.04 189.25 189.45237.78 189.65 189.85 190.05 190.25 190.46 190.66 190.86 191.06 191.26 191.46243.33 191.67 191.87 192.07 192.27 192.47 192.67 192.87 193.08 193.28 193.48248.89 193.68 193.88 194.08 194.28 194.48 194.68 194.88 195.09 195.29 195.49254.44 195.69 195.89 196.09 196.29 196.49 196.69 196.89 197.09 197.29 197.49260.00 197.69 197.89 198.09 198.29 198.49 198.70 198.90 199.10 199.30 199.50

NOTE: This chart converted from Fahrenheit chart using formula °C= ((°F-32)/1.8)



55

Checking the RTD Transmitter TMS #3

1. With control power off, connect a 100-ohm resistor to terminals #3 and #4 of thetransmitter.

2. Turn control power on, the OUI reading should be 32°F (0°C) ±10%.3. If the reading is not within specification, the transmitter may be faulty.

1 2 3 4

Temperature transmitter



Pin 1

Pin 25

BCM

100

OHM




Checking proper operation of the BCM and wiring TMS #4

1. Ensure control power is off. At the affected RTD transmitter, disconnect the wires attransmitter terminal #1 and #2. Connect a 4-20mA source to these terminals (Observecorrect polarity). Power up the control panel and then vary the simulator output.

2. At 12 mA (50%) the OUI should read 1/2 the RTD transmitter range; 100 or 250°F (37.7or 121.1°C). The readout should change as the simulator output is varied.

3. If the reading on the OUI is incorrect or does not change, turn control power off andreconnect the 4 to 20 mA simulator at the respective terminals at connector J1, (seeelectrical schematic for connection points).

4. Turn control power on and observe the OUI readout while varying the 4-20mA. If thereading is correct there is an open or short in the wire or terminals connecting the CMCto the RTD transmitter. If reading is not correct the BCM may be faulty.



Pin 1

Pin 25

mA

OU

T

2 WIR

E

OFF

100%

00.0%

DIA

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YC

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55

5


BCM



57

Valve Control System (VCS)Description:

The BCM generates a 4-20 mA signal for valve control. The signal is wired to the I/P (currentto pressure) transducer for conversion to a pneumatic signal for positioning the inlet orbypass control valve.

Specification:

• 4-20mA input = 3 to 15 psi output

• 60 to 120 PSIG instrument air input to I/P

Troubleshooting:


Typical Problem Probable Cause Troubleshooting ProcedureIV or BV not operating Failure of BCM VCS #1

Positioner or actuator malfunction VCS #2Failure of I/P VCS #2




Checking proper operation of the BCM and wiring VCS #1

1. With control power off, lift the wires at J3 for the suspected circuit and install a test metercapable of reading milliamps as shown below, (the pin numbers are found on theelectrical schematic).

2. Restore control power.3. If the meter reads 4 mA , the BCM is satisfactory.4. If 4 mA is not present, refer to the section titled “Control Power System”.5. Restore connections.6. Remove control power.7. Lift wires at suspected I/P, and install meter as in previous step.8. Restore control power. If the meter reads 4 mA, the BCM and wiring is satisfactory.

J3-Analog Outputs, (4-20mA) Channels 1-4


Pin 1

Pin 25

BCM

Pin 1

VDC mA

VAC Ω

mA COM V

X X X X X X X X X X X X X X X

X X X X X X X X X X X X X X X

Ω



59

Checking proper operation of the I/P and positioner VCS #2

1. Connect a 4-20 mA simulator to the I/P.2. Ensure instrument air is present at the supply connection on the I/P.3. Vary the simulator between 4-20 mA. The output of the I/P and the positioner should

follow. If the valve tracks the 4-20 mA signal correctly the I/P and the positioner aresatisfactory.

INGERSOLL-RANDCentrifugal Compressor DivisionHighway 45 SouthMayfield, KY. 42066Parts Service (800) 247-8640

mA OUT

2 WIRE

OFF

100%

00.0%

DIAL

BATTERYCHECK

LOOPON

XXXXXXMODEL CL-XXX

00.0% - 100%

555

4-20

mA

SU

RC

E O

R2

WIR

E S

IMU

LA

TO

R




Pressure Monitoring System (PMS)Description:

A Pressure Transducer (PT) is used to convert pressure (psi) to a 4-20 mA signal formonitoring by the CMC.

Component specification:

• 0-50 PSIG (344.75 kPa) range

• 0-200 PSIG (1379 kPa) range

• Power = 24 VDC

Troubleshooting:


Typical Problem Probable Cause Troubleshooting ProcedureZero OUI readout Open circuit/cable

disconnectedPMS #1, 2

Loss of power to transmitter PMS #1Malfunctioning transmitter PMS #3, 4

Erratic OUI readout Loose wire/terminal/connector PMS #1,2Incorrect OUI readout Any PMS #1, 2, 3, 4



61

Checking for Power to the Pressure Transmitter PMS #1

1. Ensure control power is off. Disconnect the wires at the suspect PT and connect avoltmeter to these wires.

2. With control power on, there should be approximately 24 VDC present at the terminals.3. If approximately 24 VDC is not present, see the section titled “Control Power System”.



Pin 1

Pin 25

BCM

SPAN

®

INGERSOLL RAND

VDC mA

VAC Ω

mA COM V

XXXXX XXXXX XXXXX

XXXXX XXXXX XXXXX

Ω




Checking proper operation of the BCM and wiring PMS #21. Ensure control power is off. Disconnect the wires at the suspect PT and connect a 4-20

mA source to the lifted wires (Observe correct polarity).2. Restore control power and then vary the simulator output.3. At 12 mA (50%) the OUI should read 1/2 the PT range. The readout should change as the

simulator output is varied.4. If the reading on the OUI is incorrect or does not change, turn control power off and

reconnect the 4 -20 mA simulator at the respective terminals at connector J1, (seeelectrical schematic for connection points).

5. Turn control power on and observe the OUI readout while varying the 4-20 mA. If thereading is correct there is an open or short in the wire or terminals connecting the CMCto the PT. If the reading is not correct the BCM may be faulty.



Pin 1

Pin 25

mA

OU

T

2 WIR

E

OFF

100%

00.0%

DIA

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55

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BCM



63

Quick check of the PT PMS #3

1. Connect an ohmmeter to the disconnected wires coming from the PT.2. If there is no continuity either the wiring or the PT is faulty.

SPAN

®

INGERSOLL RAND

VDC mA

VAC Ω

mA COM V

XXXXX XXXXX XXXXX

XXXXX XXXXX XXXXX

Ω

M

Functional PT test PMS #4

1. Remove control power.2. Remove the PT and connect a regulated air supply to the pressure connection. Power up

the CMC and vary the regulated air supply. The OUI should read the pressure beingapplied.




Digital Input System (DIS)Description:

The digital input devices associated with the CMC are on/off devices that turn on or off theassociated CMC digital input.

Typical digital device name and type:

1. Low seal air pressure (Pressure)

2. Low cooling water flow (Flapper)

3. Low oil level (Float)

4. High condensate level (Float)

5. Dirty inlet filter (Differential pressure)

6. Dirty oil filter (Differential pressure)

7. High motor temperature (Thermistor)

Troubleshooting:


Typical Problem Probable Cause Troubleshooting ProcedureFalse alarm or trip Faulty device DIS #1

Faulty wiring DIS #1



65

Checking proper operation of the digital devices DIS #11. Verify approximately 24 VDC is present as described in the section titled

“Troubleshooting the Power System”.2. If approximately 24 VDC is present, install a multimeter with VDC selected between J4 or

J5 pin1 and the input pin (the input pin can be determined from the electrical schematic,or wire number).

3. Ensure the digital device is not in the trip condition, the meter should read 0 VDC.4. Actuate the switch, the meter should read approximately 24 VDC.

J3-Analog Outputs(4-20mA)Channels 1-4

Pin 1

Pin 1

J4-Digital (Discrete)Inputs (24 VDC),Channels 1-8

J5-Digital (Discrete)Inputs (24 VDC),

Channels 9-16

J6-RS232 SerialData Link (Display),

Female DB9 BCM

VDC mA

VAC Ω

mA COM V

XXXXX XXXXX XXXXX

XXXXX XXXXX XXXXX

Ω Seal Air Switch




Control Power System (CPS)Description:

The control power system provides 24 VDC to the CMC system for processing logic,displaying data, and monitoring instrumentation. The 24 VDC power supply feeds the BaseControl Module (BCM) at connector J10. Overcurrent protection and power distribution areperformed as shown below:

F100

F101

F102

F103

All BCM Fuses are 5x20mm,GMA 1.5 amp, Fast Blow

Fuse 5A/250VAC, normal blo.

Power Supply

BCM

J2

+24 VDC pins 11 thru 14

Return pins 7 thru 10

J1

AC1 pin 1

AC2 pin 3

J12-Digital Output Power 120 or 220 VAC (Pin 1)

J10-Power Input (24 VDC)

J9-Current Transformer(0-5 amp)

J4 & J5 - Digital Input Power 24 VDC (pin 1)

J3- Analog Output Power 24 VDC (pins 2 & 8) J1- Analog Input Power 24 VDC (pin 26)

Digital Input Power

Analog Input/Output Power

CPU Power

F1

LEGEND:

WireTrace

To OUI J2 pin 2

To OUI J2 pin 1

To Ground Bar

BCM showncover removed

OUI Power



67

Power Supply:

• Input power: 85-132 VAC, or 180-264 VAC (auto-selecting input), 2.5A RMS max, 47-63Hz.

• Output power: 24 VDC, 4.3 A maximum at 50 °C.

Troubleshooting:



All analog inputs are zero or negative on System Page No AC power CPS #1No DC power CPS #2No analog inputpower

CPS #5

OUI displays: “INGERSOLL-RAND CentrifugalCompressor Division”

No CPU power CPS #8

BCM problems CMCS #3OUI is black No AC power CPS #1

No DC power CPS #2No OUI power CPS #7

Event Log indicates all digital alarms and trips active No AC power CPS #1No DC power CPS #2No digital inputpower

CPS #3

All digital outputs not working No AC power CPS #1No DC power CPS #2No digital outputpower

CPS #4

All analog outputs not working No AC power CPS #1No DC power CPS #2No analog outputpower

CPS #6

No AC power CPS #11. Ensure control power is off.2. Install a multimeter set for VAC between pins 1 and 3 at connector J1 on the power

supply.3. Restore control power, the meter should read 120 VAC or 220 VAC depending upon the

rated supply power. The rated supply power can be verified from the electricalschematic.




No DC power CPS #21. Ensure control power is off.2. Install a multimeter set for VDC between pins 11-14 and 7-10 at connector J2 on the

power supply.3. Restore control power, the meter should read approximately 24 VDC. If approximately

24 VDC is not present, check F1 on the power supply, if fuse is good, the power supplymay be faulty.

4. Ensure control power is off.5. Install a multimeter set for VDC between pins 1 and 2 at connector J10 on the BCM.6. Restore control power, the meter should read approximately 24 VDC. If approximately

24 VDC is not present, check the wiring between the power supply and the BCM.

No digital input power CPS #31. Ensure control power is off.2. Install a multimeter set for VDC between pin 1 at connector J4 on the BCM and the

ground bar.3. Restore control power, the meter should read approximately 24 VDC. If approximately

24 VDC is not present, check F103 on the BCM, if F103 is good, check for DC power.

No digital output power CPS #41. Ensure control power is off.2. Install a multimeter set for VAC between pin 1 at connector J12 on the BCM and the

ground bar.3. Restore control power, the meter should read 120 VAC or 220 VAC depending upon the

rated supply power. The rated supply power can be verified from the electricalschematic.

No analog input power CPS #51. Ensure control power is off.2. Install a multimeter set for VDC between pin 26 at connector J1 on the BCM and the



No analog output power CPS #61. Ensure control power is off.2. Install a multimeter set for VDC between pin 2 at connector J3 on the BCM and the



No OUI power CPS #71. Ensure control power is off.2. Install a multimeter set for VDC between pins 1 and 2 at connector J1 on the OUI.3. Restore control power, the meter should read approximately 24 VDC. If approximately




69

No CPU power CPS #81. Ensure control power is off.2. Verify approximately 24 VDC is present at J10.3. Check F100, if F100 is blown the BCM must be replaced, not the fuse.4. If F100 is not blown, and the BCM is not functioning, the BCM must be replaced.




Controller ProblemsDescription:

The CMC System is generally comprised of a Base Control Module (BCM), Operator UserInterface (OUI), and Power Supply (PS). There are few user serviceable components withinthe system, however, a brief understanding of the system will help in overall troubleshooting.All components require 24 VDC and rely on hardware and software to perform correctly, ifthe problem cannot be isolated to a power problem it is most likely a hardware or softwareproblem, which will require Ingersoll-Rand support to correct.

Component Specification:

• VDC power required

• Software required

Troubleshooting:



BCM fault suspected No power CMCS #4OUI is dim Wrong contrast selected CMCS #1

Backlight failing CMCS #1OUI is black No power CMCS #2OUI displays “INGERSOLL-RANDCentrifugal Compressor Division”

Cable disconnected CMCS #3

OUI displays “Status XXH”Where XX is a specific number

Many Refer to Status Codesunder System InformationSection.

MODBUS communications problem No power CMCS #5Many Refer to the UCM Section.



71

BCM ProblemsBCM is not controlling CMCS #41. Check the CPU power as described in the section titled “The Control Power System”.

OUI ProblemsOUI is dim CMCS #11. Depress the contrast key to step to the desired brightness.2. Replace the OUI backlight as described in the section titled “Backlight Replacement

Procedure”. If the backlight does not fix the problem the OUI may be faulty.

OUI is black CMCS #21. Check for OUI power as described in the section titled “The Control Power System”. If

approximately 24 VDC is present the OUI may be faulty.

OUI displays “INGERSOLL-RAND Centrifugal Compressor Division” CMCS#3

1. Check the cabling between OUI J1 and BCM J6.2. The BCM may require programming.3. Check the BCM CPU power.4. The BCM may be faulty.

UCM ProblemsAll UCM LED’s are not lit CMCS #51. Check for approximately 24 VDC at pins 1 and 2 at J3 on the UCM.2. If power is present at J3 the UCM may be faulty.




OptionsThis section details the various standard options that are available for the CMC. Some of theoptions listed are provided standard on some models, and will be indicated as such.

EnclosuresThe CMC has three panel enclosures available; NEMA 12 (IP 64) which is standard, andoptional NEMA 4 (IP 65) and NEMA 4X (IP 65). The panel is machine mounted. All electricaldevices are mounted and wired where practical.

NEMA 12 (IP 64)NEMA 12 is the standard enclosure for all compressors with CMC panels. NEMA definesthis rating as "... intended for indoor use primarily to provide a degree of protection againstdust, falling dirt, and dripping non-corrosive liquids. They shall meet drip, dust, and rust-resistance design tests. They are not intended to provide protection against conditions suchas internal condensation.” Typically this type of enclosure is applied for most indoorapplications.

Cooling FanThe cooling fan is supplied on all standard CMC enclosures, where a wye-delta motorstarter is present, the Control Electrical Package is included, or the ambient temperatureexceeds 40°C keeps the internal temperature below the maximum operating temperatureallowed. This action effectively extends the operating life of the control components. A filterand gasket are added to attain a NEMA 12 rating.

NEMA 4 (IP 65)This optional enclosure type is applied for most outdoor applications. Indoor applications thatare subject to hose washing would also apply to this standard. NEMA defines this rating as"... intended for indoor and outdoor use primarily to provide a degree of protection againstwindblown dust and rain, splashing water, and hose directed water; and to be undamagedby the formation of ice on the enclosure. They shall meet hose down, external icing, andrust-resistance design tests. They are not intended to provide protection against conditionssuch as internal condensation or internal icing."

The standard panel enclosure is replaced with a new box that meets the aboverequirements. The User Terminal vinyl overlay and sealing bezel is door mounted andallows direct interface with the environment. NEMA 4 rated lights, switches and buttons aremounted directly through the panel door. A panel space heater and Vortex Tube Cooler areadded to accommodate changes in ambient temperatures.

NEMA 4X (IP 65)Also an optional enclosure type that should be applied in the same type of NEMA 4applications within corrosive environments. The basic difference between NEMA 4 andNEMA 4X is that the panel enclosure is constructed with stainless steel.



73

Space HeaterRequired for NEMA 4 and NEMA 4X panels to protect the panel from internal condensation.This option should also be used with NEMA 12 for unheated building applications.

Vortex Tube CoolerThis panel cooler is required on NEMA 4 and NEMA 4X enclosures to maintain the operatingtemperature below the maximum. An adjustable thermostat is provided to open and close asolenoid operated valve from the instrument air header in the panel. The cooler works byconverting filtered compressed air into a hot air stream and cold air stream. The hot airstream is vented external to the enclosure and the cold air stream is directed into theenclosure.

Type Z PurgeThe CMC requires a Type Z Purge when the customer environment is Division 2. A Type ZPurge reduces the classification within an enclosure from Division 2 too non-hazardous.When provided, a NEMA 4 or NEMA 4X enclosure is required. Hand valve selectable quickand slow purges, with flow meters are provided to regulate the amount of gas entering thepanel. A differential pressure switch is wired to a light on the front of the panel to indicate ifthere is a loss of purge gas. A relief valve is installed to prevent over-pressurization and awarning label, text below, is affixed to the front of the panel.

WARNING

Enclosure shall not be opened unless the area is known to be non-hazardousor unless all devices within the enclosure have been de-energized. Power shall not berestored after the enclosure has been opened until combustible dusts have beenremoved and the enclosure re-pressurized.

Fused Control Power DisconnectAs a safety precaution, this option removes power from the panel before the door is opened.By turning the rotary door handle, the panel power is terminated. If the disconnect is toinclude fuse size provisions for the main motor starter, additional information is required.The disconnect would have to be mounted external to the panel enclosure. The short circuitcapacity, maximum ground fault, motor full load amps, motor locked rotor amps and motorvoltage must be known to size the disconnect properly. Pricing varies depending upon thesize, amp rating of the fuse, which is required for protection.

NOTE

This option does not make fuse size provisions for the main motor starter.




Control Electrical PackageThe Control Electrical Package consists of a Control Transformer, Prelube Pump Starter,Oil Heater Contactor(s) and Transient Voltage Surge Suppressor. This option allows thecustomer to bring a single source of electrical power to the compressor to run all of thecompressor package accessories; thereby, making compressor installation easier.

Stage Data PackageFor monitoring of interstage pressure and temperatures, the Stage Data Package can beadded. As standard, the CMC comes with temperature readout, alarm and trip for the next tolast compression stage and compressor discharge pressure indication. When selected,each stage gets temperature and pressure measurements on the downstream side of eachstage's cooler. For compressors without built-in aftercoolers, the last stage diffusertemperature is measured. Each temperature has readout, alarm and trip capability while thepressures are readout only.

Alarm HornThe optional alarm horn sounds any time there is an alarm or trip situation. The horn outputwill pulse for an alarm and remain constant for a trip. This allows the operator to distinguishbetween each fault type without viewing the OUI. The horn silence push-button is located onthe CMC faceplate to silence any audible devices connected to the CMC board.

Running Unloaded Shutdown TimerThe intent of this option is to save energy by shutting the compressor off during extendedperiods of unloaded operation. When the running unloaded shutdown timer is enabled withthe RUNNING UNLOADED SHUTDOWN TIMER DISABLED/ENABLED selector switch, theauto-dual control mode should be selected, this provides for automatic unloading of themachine during periods of low demand.

Water Solenoid Post Run TimerThis optional panel function is used to shut off water flow to the air and oil coolers after thecompressor is stopped. It is accomplished by sending a signal to close the solenoidoperated water valve(s).

Panel Mounted Wye-Delta StarterMain motor starter enclosed in the CMC panel. This feature allows the customer to wire thecompressor from a single source; thereby, eliminating most electrical wiring and starterinstallation expense. These starters are available for compressors with motors up to 350 HPand 575 Volts.

N.O. Contact for Remote Indication of Common Alarm andTrip

A normally open contact for individual remote indication closes whenever an alarm or tripoccurs. This allows a customer to have remote indication of compressor alarm, trip or both.

Power Regulating Constant Voltage TransformerIf the electrical power supplied to the CMC varies more than ten percent, this transformermust be added to bring the voltage within the specification requirements.



75

Automatic Starting

NOTE

Most electric motors are only rated for two cold starts or one hot start per hour. It isthe operator’s responsibility not to exceed the electric motor’s limitation. The controlsystem allows the compressor to be started when the compressor is ready, not themotor.

Remote start and stop through hard wiring to the compressor control panel, communicatingthrough the MODBUS port via RS422/485, Auto-Hot Start and Auto-Cold Start are the fouroptions for automatically starting and stopping with the CMC. With each of these options aREMOTE COMMUNICATIONS DISABLED/ENABLED or REMOTE FUNCTIONSDISABLED/ENABLED, selector switch is provided on the device plate with a REMOTEENABLED light. Since each option performs basically the same function, only one should bepurchased for a single CMC. The specific method selected depends upon the application.

Remote Start and Remote Stop – HardwiredWhen this option is purchased, two digital inputs are configured on the CMC Base ControlModule, one for remote start and one for remote stop.

Remote Start Digital InputThis input is driven by a momentary contact closure of at least 120 milliseconds. For thestart to proceed, the panel power must be on, the compressor must be in the Ready state(all utilities must be running and permissive functions satisfied) and the REMOTEFUNCTIONS DISABLED/ENABLED selector switch is in ENABLED mode prior toenergizing the input.

Remote Stop Digital InputThis input is driven by a maintained contact closure. The remote stop input is always active;that is, the remote stop can be initiated regardless of the REMOTE FUNCTIONSDISABLED/ENABLED selector switch position.

CommunicationsRemote starting and stopping can be accomplished through the MODBUS communicationport in various ways. See the section on Communications that follows for these options.Again, panel power must be on, all utilities must be running and permissive functionssatisfied in order for the start-up to proceed.

Auto-Hot StartNormally purchased in multiple compressor applications where backup air is required, thisautomatic starting option allows the compressor to be started when the system air pressureis below a user selected set point pressure.

Panel power must be on, all utilities must be running, the AUTO HOT STARTDISABLED/ENABLED selector switch must be in the ENABLED position and all permissivefunctions satisfied in order for the start-up to proceed. Solenoid water valve(s) are providedfor the intercooler(s) to reduce water consumption when the compressor is not running. A




post run timer is also included in the Auto Hot Start logic to de-energize the water solenoidvalves twenty minutes after a compressor stop or trip to allow the oil to cool.

Auto-Cold StartThis option is very similar to Auto-Hot Start with the exception that the compressor startswith no initial panel power. An additional timer is added to simulate the start button beingpressed and another timer is added to bypass the low oil temperature function on start-up.One additional solenoid valve is included for instrument air supply. The CONTROL POWEROFF/ON selector switch label is modified to CONTROL POWER LOCAL/OFF/COLDSTART. When in the COLD START position, the compressor is OFF and can be startedthrough the Auto-Cold Start function. As a safety precaution, an optional strobe light can beprovided to indicate that an automatic start is about to begin.

Remote 4-20 mA Pressure SetpointWhen the REMOTE FUNCTIONS DISABLED/ENABLED selector switch is in the ENABLEDposition, the CMC will monitor the specified analog input for pressure setpoint. If this analoginput’s value minus the Pressure Setpoint (from the display) is greater than or equal to thedisplay’s Pressure Setpoint step value (default 0.1 psi), a remote setpoint change will berequested. This request will be initiated, as long as there are no analog input error faults forthis channel, and the change made will rounded to the nearest step value (0.1) size. Thismethodology prevents the control system from chasing an ever-changing analog inputvalue.

Steam and Gas Turbine Driven CompressorsThe following describes the differences between the motor and turbine driven compressorlogic.

Performance Control

Motor Current, MinLoad and MaxLoadSteam and gas turbines do not have motor current, MinLoad and MaxLoad operatedifferently form the normal motor driven compressor. MinLoad uses an inlet valve position,instead of amps, to determine when to transition from Inlet Valve Pressure control to BypassValve Pressure control. When in MinLoad, the controller uses this valve position as thesetpoint for the Inlet Valve MinLoad PID loop. Since the controlled variable and the setpointvariable are identical, the goal of tuning this loop is to get a steady output. The defaultparameters will satisfy most all applications. The procedure for determining the MinLoadpoint is the same for both motor and turbine driven units, except inlet valve position isrecorded instead of motor amps.

CAUTION

Improperly tuning MinLoad PID values will result in unpredictable compressoroperation. If this situation arises, reset the PID values to the default values.

MaxLoad situations are detected on turbine driven compressors by low speed. The MaxLoadsetpoint is a speed below the rated speed and above the low speed alarm. This speed isdetermined by adding an offset to the low speed alarm. This offset is the speed that thegovernor can accurately control.



77

Compressor Operating StatesTurbine Driven Packages

Stopped+

Waiting

Not ReadyReady

Compressor+

+ Rotating

Starting

Accelerate-1

Accelerate-2

Slow Rolling

Loading

Unloaded

MinLoad

Loaded

Full Load

MaxLoad

A-D Unloaded

Surge Unload

Unloading

Coasting

Surge ControlAll surge related issues are identical to motor driven units with the exception of the detectionmethodology.

How Surge is DetectedThe CMC senses surge when the rate of change in last stage discharge pressure is greaterthan the surge sensitivity setpoint value. The difference between this and motor driven unitsis that the motor driven units uses rate of change in motor amps also.

Compressor Operating MethodologyComparing the chart to the right forTurbine driven compressor and Motordriven compressor, the only statedifferences are the addition of the firstthree states under Rotating. These areAccelerate-1, Accelerate-2 and SlowRolling.

Accelerate-1This state is provided to give the operatorfive minutes from the time the Start buttonis pressed to get enough steam to theturbine to get the speed above the ZeroOffset Speed. This speed is defaulted to15 rpm. If this speed is not achieved in thistime period, the event message“Accelerate-1 Fail” will appear and thecontroller will trip the compressor. Asalways, the compressor must be “Ready”before the start button is pressed. Thereason for the five-minute limitation is toprevent the compressor from being readyfor an indefinite period of time. Thisprevents the operator from forgetting thatthe compressor is ready to accelerate.“Accelerate-1” could also be explained as“accelerating to zero speed offset” or“waiting for compressor rotation”.

Accelerate-2After the transition to Accelerate-1 is complete, this state is initiated when rotation isdetected and the turbine has not reached the low trip speed. This state may be bypassed ifthe turbine accelerates very quickly.

Once in this state, a sixty (60) second timer is initiated. If the speed does not get to theminimum slow roll speed within this time period, the event message “Accelerate-2 Fail” willappear and the controller will trip the package. This state is limited sixty (60) seconds toprevent bearing damage from rolling the compressor at too low a speed. The bearing designrequires a minimum speed to form the oil film thickness required for proper bearing




operation. “Accelerate-2” could also be explained as “accelerating to minimum slow rollspeed”.

Slow RollingAfter the transition to Accelerate-2 is complete, this state is entered after the previous sixty-second timer has elapsed and the speed is less than the low trip speed. The compressorcan operate in this “Slow Rolling” state indefinitely. While in this state, if the speed dropsbelow the minimum slow roll speed, the event message “Slow Roll Fail” will appear and thecontroller will trip the compressor. If at any time during “Slow Rolling” the speed exceeds themaximum slow roll speed, the compressor will transition to “Starting”. The Starting state forturbine driven compressors is the same as for motor driven compressors.

Quick Start TurbinesQuick Start turbines may skip “Accelerate-2” and “Slow Rolling” or just “Slow Rolling”because of the acceleration characteristics. The acceleration sequence depends upon theacceleration characteristics for a given turbine.

Operator User Interface (OUI)

Status BarMotor driven compressors have an optional Compressor Status Field for Start Disabled.This field is standard for turbine driven compressors and it means that the turbine trip andthrottle valve limit switch has not been made.

System FolderReplacing “Motor Current “with” Compressor Speed” on Page 1 is the only modification tothis folder.

Info FolderThe events “Starter Failure” and ”Loss of Motor Current have been deleted from the possibleevent list. The following events have been added.

Possible Events ListEvent Name Description

Accelerate-1 Fail The zero offset speed has not been achieved before the end of the five-minute timer.

Accelerate-2 Fail The minimum slow roll speed has not been achieved before the end of the one-minute timer.

Driver Trip The trip and throttle valve limit switch has been latched, then unlatched.

Governor Common Trip The governor has tripped.

High Speed Alarm The indicated speed is greater than or equal to the High Speed Alarm setting.

High Speed Trip The indicated speed is greater than or equal to the High Speed Trip setting.

Illegal Rotation Rotation has been detected when in “Stopped”.

Low Speed Alarm The indicated speed is less than or equal to the Low Speed Alarm setting.

Low Speed Trip The indicated speed is less than or equal to the Low Speed Trip setting.

Slow Rolling Fail The minimum slow roll speed was not maintained during “Slow Roll”.

Starting Fail The low trip speed was not achieved before the end of the Starting Timer.

TTV Switch Fault The trip and throttle valve (TTV) limit switch is made when the (TTV) solenoid is de-energized.



79

Settings FolderFor Page 2, Anti-Surge and Driver Over-Load Protection …

1. “MaxLoad (HLL), amps” is replaced with “MaxLoad (HLL), rpm”.

2. “User Setpoint (TL), amps” is replaced with “User Setpoint (TL), IV Pos %”.

3. “Control Setpoint, amps” is replaced with “Control Setpoint, IV Pos %”.

4. “Surge Index Increment, amps” is replaced with “Surge Index Increment, IV Pos %”.

For Page 5, Miscellaneous

1. “CT Ratio” is removed.

2. “Motor Failure Trip Enable” checkbox is removed.




General Sequence of Operation

Starting Methodology1. The panel power is turned on. The compressor is WAITING.

2. The CMC Panel mounted switch for DRIVER SPEED RATED/IDLE (when supplied foran electronic governor) should be put into the IDLE position. This switch is wired to adiscrete input (Driver Speed Rated/Idle) in the CMC and is sent on the discrete output(Driver Speed Rated/Idle) to the governor.

3. When the two-minute waiting timer has expired, the compressor is NOT READY.

Un

load

ed

Co

asti

ng

Sta

rtin

g

Lo

adin

g

Lo

aded

Min

Lo

ad

Fu

ll L

oad

Max

Lo

ad

Un

load

ing

Un

load

edPower

On

Zero Speed Offset (15 rpm)

Minimum Slow Roll (25%)

Maximum Slow Roll (50%)

Low Alarm (95%)

MaxLoad (HLL)

Low Trip (93%)

Rated "Full Load" (100%)

Overspeed Alarm (105%)Overspeed Trip (108%)Mechanical Trip (110%)

(0%)

SPEED

RotatingStopped

Compressor Operating Statesfor Turbine and Diesel Driven Packages

No

t R

ead

y

Rea

dy

Wai

ting

AnyStops or

Trips

Start

NoStops orTrips and

Latch



81

4. Reset the governor to clear any trip signals. This may be accomplished with the digitaloutput (Reset – Momentary). If an electronic governor exists, a discrete output signal(Common Trip) is sent from the governor to a discrete input signal on the CMC when thegovernor needs to trip the compressor. If no electronic governor exists, a jumper mustbe installed on the CMC board.

5. When NO Trips exist (compressor and turbine), the CMC energizes the turbine’s tripand throttle valve (TTV) solenoid. This is accomplished through a discrete output (DriverPermissive) from the CMC to the TTV solenoid.

6. At this point, the compressor is NOT READY, Driver Disabled.

7. When the TTV solenoid is energized, the turbine trip valve can be latched.

8. When the turbine trip valve is manually latched, the turbine trip valve’s limit switch will beenergized. This signal is sent to a discrete input (Trip and Throttle Valve Limit Switch) onthe CMC.

9. When the limit switch is energized and no stop command is pending, the compressorwill be READY. This state may be maintained indefinitely.

10. The Start Key is pressed on the compressor. The digital output (CR1) is energized toactuate the solenoid operated steam valve and the digital output (Start – Momentary) isenergized. A timer (five minute maximum) is started. At this point, enough steam shouldbe applied to the turbine to get the speed above the zero speed offset. This period isACCELERATE-1.

11. Once the zero speed offset has been established, a one minute timer is provided toprevent compressor pinion damage from rotating the pinions at too low a speed for anexcessive time. The compressor bearings are designed to have a minimum oil filmpressure created by a minimum rotating pinion speed. Therefore, we must not stay at

Accelerate-1

Accelerate-2

Slow Rolling

Starting

Accelerate-1

Accelerate-2

Starting

Accelerate-1

Starting

Adaptive StartingTM Techniques

Zero Speed Offset (15 rpm)

Minimum Slow Roll (25%)

Maximum Slow Roll (50%)

Low Trip (93%)

(0%)

SPEED




too slow a speed for an extended period. This is ACCELERATE-2. The turbine mustreach the Minimum Slow Roll Speed (approximately 25% of Full Speed) to continue.

12. Once the turbine gets past the Minimum Slow Roll Speed and is less than the MaximumSlow Roll Speed (approximately 50% of Full Speed), the turbine is in the slow rollingzone and the compressor is SLOW ROLLING. The User may leave the compressor inthis mode indefinitely. The CMC monitors the compressor speed (through the speedanalog input) in this mode. The Idle/Rated Driver Speed switch is turned to the Ratedposition.

13. When the turbine speed exceeds Maximum Slow Roll Speed, the Starting Timer begins(60 seconds maximum) and is STARTING. This is the same time for motor drivencompressors; therefore, the User must put enough steam to the turbine to get the speedabove the low trip speed before the timer expires. At this point, the compressor hasstarted and runs as described elsewhere.

Instrumentation for Turbine Driven Compressors

Centac Microcontroller

Turbine Compressor

ElectronicGovernor

Discrete Outputs (DO)

Discrete Inputs (DI)

TTV Solenoid Energize (Driver Permissive)

CR1

Analog Input (AI)

TTV Limit Switch

Driver SpeedRated/Idle

Switchon Panel

Door

Common Trip

Start - Momentary

Stop - Momentary

Reset - Momentary

Speed

DI

AO

AI

Solenoid Steam Valve

Trip Valve

TTV Solenoid

Manual LatchLimit Switch

Steam

Throttle Valve

DO

Speed

Driver Speed Rated/Idle



83

Diesel Driven CompressorsDiesel driven compressors have similar characteristics as the turbine driven compressors.The differences are…

1. “Idle/Rated Driver Speed” discrete input and discrete output are eliminated.

2. “Start – Momentary”, “Stop – Momentary” and “Reset – Momentary” discrete outputsare eliminated.

3. “Driver Permissive” discrete output is wired to the “Trip and Throttle Valve Limit Switch”discrete input.




CommunicationCustomers may want to communicate to the CMC control systems for remote compressorcontrol and monitoring. This communication capability provides for flexibility in thecustomer's compressed air operation through remote start and stop, data gathering forpreventative maintenance, and incorporation into plant-wide control system.

The major avenue for communicating with the CMC is via MODBUS protocol over anRS422/485 hardware link. This requires hardware for the control panel, and acommunications device with the appropriate driver software to perform the desired panelfunctions. The RS422/485 interface can communicate with any serial device that has anRS422 or RS485 port. The customer or his representative must write system software tosuit his individual needs for remote control and monitoring. Since the customer writes thisinterface, the system can be as flexible as the customer desires.

Centac Energy Master (CEM)CEM is a pre-written, software package available for compressors with CMC panels. Thissoftware features Controlled Surge Reset and Reload, Compressor Rotation, AutomaticTimed Logging of Compressor Data, Event Logging of Trip, Alarm, and Surge, Load Sharingand Adaptation to Compressor Loading Schedule. Even with this feature rich set ofcapabilities, some users may want more or different options.

For example, some users might want to display multiple compressors on a single screen,but currently each compressor is on a separate screen (see CEM Instruction Manual fordetails). A user might want to log specific data rather than all data. The options are endless.Adding each of these features requires reprogramming and testing (custom programming).Currently, these custom modifications are not available.

Direct CMC Communications with RS422/485For the descriptions that follow, a serial device can be a Personal Computer (PC),Programmable Logic Controller (PLC), Distributed Control System (DCS) or any otherdevice that can transmit, receive and interpret an RS422/485 formatted signal over ahardware link. In the descriptions that follow, the PC and PLC serial devices are not specificto manufacturers or operating systems.

There are many ways of interfacing to CMC control systems through an RS422/485 port.Most of the following methodologies are currently available; but please be aware, otherpossible configurations can exist.

All RS422/485 interfaces require custom interface software and custom applicationsoftware. The interface software allows a specific serial device and operating system totransmit, receive and interpret data from a CMC control system. The application softwaretells the CMC control system what to do; for example, start compressor when ready, stopcompressor after midnight and retrieve the current data and save to a disk file.

Currently there are hundreds of different serial devices using different operating systemsand languages in the industrial equipment world. Therefore, the practicality of having aninterface for many systems is limited. Custom interfaces must be written as required by thehardware and operating system used.

The capabilities of the hardware and the imagination of the developer only limit theapplication software. For example, one developer may have two compressors. In this



85

application the developer wants a screen to display the compressor interstage pressure andtemperatures for both machines with various other compressor data. A second developerhas five compressors. He also wants to display the same data, but this time for all fivemachines. The only way this is done is through changing the application software (custommodification).

The developer may write functions to read and display data, log that data to some magneticmedia for storage, change compressor set points, sequence the compressors for efficientoperation and network additional devices, such as pumps, dryers, etc., into the system. Allof these functions require specially written application software for the intended use.

The CMC-MODBUS InterfaceIntroduction

The CMC can communicate with other devices over a variety of communications standards.Supported standards, or protocols, include RS-232, IRBUS (Ingersoll-Rand Proprietary),and Modicon’s MODBUS. The built-in ports on the CMC’s optional Universal CommunicationAdapters access communications. The CMC-MODBUS Interface defines the messagestructure that a CMC uses to exist on a MODBUS network. This interface will allow theMODBUS network to gather information and control the compressor.

NOTE

Unless specified otherwise, numerical values (such as addresses, codes, or data) areexpressed as decimal values in the text of this section. They are expressed ashexadecimal values in the message fields of the examples.

In order to communicate over other types ofnetworks, a network adapter must be used. Theinformation presented in the following sections doesnot include MODBUS protocol details like framingmessages and calculating checksums. This detailedinformation can be obtained from SnyderAutomation’s MODBUS PROTOCOL Manual,Chapters 1 through 6. This can be obtained throughthe Internet at “www.modicon.com”.

Serial ModesMODBUS Controllers can be setup to communicateon MODBUS networks using either of twotransmission modes: ASCII or RTU. The CMCsupports only the RTU mode. The user mustspecify the serial port communication parameters(baud rate, parity mode, etc.) during configuration ofeach CMC. The mode and serial parameters mustbe the same for all devices on a MODBUS network.

DeviceAddress

FunctionCode

DataAddress

Data

CRC

Master

Response

Query

DeviceAddress

FunctionCode

ByteCount

Data

CRC

Slave

Figure 13: MODBUS Messages




MODBUS MessagesA MODBUS network uses a master-slave relationship. The CMC always acts as a slavedevice. The slave cannot initiate a message, and returns a message (response) only toqueries (reads) that are addressed to them individually. For example, a force coil command(write to module) that is broadcast to all MODBUS devices would not get a response.Responses are not returned to broadcast writes from the master.

Device AddressThis address is the physical address of the Universal Communication Module (UCM) for thecompressor. This address must be unique in the MODBUS network. The valid range for thisaddress is 01-FF (hexadecimal). NOTE: 00 (hexadecimal) is reserved for broadcast.Configuration of the slave address is available through the Ingersoll-Rand Service Tool andwill be provided by a certified Ingersoll-Rand Service Representative.

Function CodeThe listing below shows the function codes that are supported by the CMC. Additional detailabout each function is provided in sections that follow.

Data AddressesAddresses that contain the data type and a four-digit number are referred to as absolute(e.g., address 30232, where 3 is the data type for a input register and 0232 or 232 is theaddress). Software products at the operator or user level use absolute addresses mostfrequently.

The addresses that do not contain the type and are referenced to zero are referred to asrelative (e.g., absolute address 30232 would be relative address 231, remove the data type3, holding register, and subtract 1 for referencing to zero). All data addresses in MODBUSmessages (typically, behind the scenes at the programming communication level) arereferenced to zero; that is, the first occurrence of a data item is addressed as item numberzero.

FunctionCode

(decimal)

Function Code(hex)

Function Name

1 01 Read Coil Status2 02 Read Input Status3 03 Read Holding Registers4 04 Read Input Registers5 05 Force Single Coil6 06 Preset Single Register

15 0F Force Multiple Coils16 10 Preset Multiple Registers

Reference Data TypeMODBUS

RangeAbsolute

Addresses

MODBUSRange

RelativeAddresses

CMC RangeAbsolute

Addresses

CMC RangeRelative

Addresses

0x Coils 00001-09999 0000-9998 00001-09000 0000-89991x Discrete Inputs 10001-19999 0000-9998 10001-19000 0000-89993x Input Registers 30001-39999 0000-9998 30001-39000 0000-89994x Holding

Registers40001-49999 0000-9998 40001-49000 0000-8999



87

• Absolute address for Coil 00127 decimal is relatively addressed as coil 007E hex (126decimal)

• Input register with absolute address of 30001 is relatively addressed as register 0000 inthe data address field of the message. The function code field that specifies reading orwriting data already specifies an input register operation; therefore, the 3x reference isimplicit.

• Holding register with an absolute address of 40108 is relatively addressed as register006B hex (107 decimal)

Single Module AddressesThe addresses provided in this document are for compressors with a single Base ControlModule.

Multiple Module AddressesFor those systems that require multiple Base Control Modules, the addresses for the firstmodule will be as provided within this document. The addresses for the second module willbe provided as an engineering submittal.

DataFor both queries and responses, the data is in sixteen bit (two bytes, one word) chunks. Foreach two byte word, the left most byte is the most significant. For each byte, the left most bitis the most significant.

This portion of the message changes with each function code. See the detail that follows foreach function for the specifics of this message component.

Byte CountThe number of bytes contained in the data portion of the message. This is used on bothqueries (reads) and responses.

Cyclical Redundancy Check (CRC)This portion of the message is used to prevent incorrect data from being used in the Masteror Slave because of communication errors.

Function Details

Function 01 - Read Coil StatusThis function reads the state of one or more coils (MODBUS 0x references) in the slave(CMC Base Control Module). For the CMC, these coils represent the Discrete (Digital)Outputs, compressor operating state (see the Operator User Interface Status Bar fordefinition), any compressor Trip condition and any compressor Alarm condition. If thefunction returns a 1, the discrete output is on. If the function returns a 0, the discrete outputis off. Broadcast is not supported. Refer to the table on the next page for MODBUS AbsoluteAddresses for each coil supported by the CMC-MODBUS Interface.




Example: Reading a Single CoilAfter reviewing the Electrical Schematic for your compressor, you determine that the digitaloutput for the prelube pump is located on J12-P7,8 (Channel 13). From the table above, theAbsolute Address is decimal 00199 (Relative Address is hexadecimal 00C6) for the outputin question. Therefore, to read the state of the prelube pump output the following commandis issued (the following data are presented in hexadecimal format):

The response from this command is:

The data (01) means that the discrete output is on, or the prelube pump is running.

Absolute

Address(decimal

)

RelativeAddress

(hex)Coil Name - Read Only*

Absolute

Address(decimal

)

RelativeAddres

s(hex)

Coil Name - Read Only*

00187 00-BA Digital Output, Channel 1 (J15-P7,8) 00203 00-CA Compressor State - Waiting00188 00-BB Digital Output, Channel 2 (J15-P5,6) 00204 00-CB Compressor State - Coasting00189 00-BC Digital Output, Channel 3 (J15-P3,4) 00205 00-CC Compressor State - Starting00190 00-BD Digital Output, Channel 4 (J15-P1,2) 00206 00-CD Compressor State - Not Ready00191 00-BE Digital Output, Channel 5 (J14-P7,8) 00207 00-CE Compressor State - Ready00192 00-BF Digital Output, Channel 6 (J14-P5,6) 00208 00-CF Compressor State - Surge Unload00193 00-C0 Digital Output, Channel 7 (J14-P3,4) 00209 00-D0 Compressor State - Autodual Unload00194 00-C1 Digital Output, Channel 8 (J14-P1,2) 00210 00-D1 Compressor State - Unloading00195 00-C2 Digital Output, Channel 9 (J13-P7,8) 00211 00-D2 Compressor State - Unloaded00196 00-C3 Digital Output, Channel 10 (J13-P5,6) 00212 00-D3 Compressor State - Min load00197 00-C4 Digital Output, Channel 11 (J13-P3,4) 00213 00-D4 Compressor State - Max load00198 00-C5 Digital Output, Channel 12 (J13-P1,2) 00214 00-D5 Compressor State - Loading00199 00-C6 Digital Output, Channel 13 (J12-P7,8) 00215 00-D6 Compressor State - Loaded00200 00-C7 Digital Output, Channel 14 (J12-P5,6) 00216 00-D7 Compressor State - Full Load00201 00-C8 Digital Output, Channel 15 (J12-P3,4) 00217 00-D8 Compressor State - Analog Input

Failed00202 00-C9 Digital Output, Channel 16 (J12-P1,2) 00218 00-D9 Any Compressor Trip

00219 00-DA Any Compressor AlarmNOTE: (J15-P7,8) is interpreted as Connector J15, Pins 7 and 8 on the Base Control Module. * IMPORTANT: These coils aredefined as read only. If you decide to write to these coils, unexpected results could occur.

Number ofDevice Function Address Coils CRC

Address Code Hi Lo Hi Lo Lo Hi01 01 00 C6 00 01 1D F7

Device Function Byte CRCAddress Code Count Data Lo Hi

01 01 01 01 90 48



89

Example: Reading Multiple CoilsTo read all sixteen digital (discrete) outputs, the following command is sent:

where relative address 00-BA is for digital (discrete) output for Channel 1. The responsefrom this command is:

To determine the state of each output, review the Electrical Schematic for your compressor.For this example, you determine that the digital output for the prelube pump is located onJ12-P7,8 (Channel 13) and the digital output for the remote trouble contact is J15-P3,4(Channel 3). The first hexadecimal data byte 04 (0000 0100 binary), represents the states ofthe first eight digital (discrete) outputs (8-1). Therefore, for this example 04 means thatChannels 8, 7, 6, 5, 4, 2 and 1 are off and Channel 3 (compressor is in an alarm or tripcondition) is on. For the next eight channels (16-9) the hexadecimal data byte 10 (0001 0000binary) means that Channels 16, 15, 14, 12, 11, 10 and 9 are off and Channel 13 (prelubepump is running) is on. The following table graphically depicts this example:

A bit response of 1 means that the output is on and a response of 0 means that the output isoff.

Function 02 - Read Input StatusThis function reads the state of one or more discrete inputs (MODBUS 1x references) in theslave (CMC Base Control Module). For the CMC, these inputs represent the Discrete(Digital) Inputs. If the function returns a 1, the input is on. If the function returns a 0, the inputis off. Broadcast is not supported. Refer to the table on the next page for MODBUS AbsoluteAddresses for each discrete input supported by the CMC-MODBUS Interface.

Number ofDevice Function Address Coils CRC

Address Code Hi Lo Hi Lo Lo Hi01 01 00 BA 00 10 1C 23


01 01 02 04-10 BA F0

Response 8 7 6 5 4 3 2 1Byte 1 0 0 0 0 0 1 0 0

Address C1 C0 BF BE BD BC BB BA

Response 16 15 14 13 12 11 10 9Byte 2 0 0 0 1 0 0 0 0

Address C9 C8 C7 C6 C5 C4 C3 C2




Example: Read Single Discrete InputAfter reviewing the Electrical Schematic for your compressor, you determine that the digitalinput for emergency stop push button is located on J4-P5 (Channel 4). From the tableabove, the Absolute Address is decimal 10174 (Relative Address is hexadecimal 00AD) forthe input in question. Therefore, to read the state of the emergency stop push button thefollowing command is issued (the following data are presented in hexadecimal format):


The data (01) means that the input is on, or the emergency stop push button is pressed.

Example: Read Multiple Discrete InputsThe method for reading multiple Discrete Inputs is the same as reading multiple coils. Seethe example for “Reading Multiple Coils”.

AbsoluteAddress(decimal)

Relative Address(hex)

Input Name - Read Only*

10171 00-AA Digital Input, Channel 1 (J4-P2)10172 00-AB Digital Input, Channel 2 (J4-P3)10173 00-AC Digital Input, Channel 3 (J4-P4)10174 00-AD Digital Input, Channel 4 (J4-P5)10175 00-AE Digital Input, Channel 5 (J4-P6)10176 00-AF Digital Input, Channel 6 (J4-P7)10177 00-B0 Digital Input, Channel 7 (J4-P8)10178 00-B1 Digital Input, Channel 8 (J4-P9)10179 00-B2 Digital Input, Channel 9 (J5-P2)10180 00-B3 Digital Input, Channel 10 (J5-P3)10181 00-B4 Digital Input, Channel 11 (J5-P4)10182 00-B5 Digital Input, Channel 12 (J5-P5)10183 00-B6 Digital Input, Channel 13 (J5-P6)10184 00-B7 Digital Input, Channel 14 (J5-P7)10185 00-B8 Digital Input, Channel 15 (J5-P8)10186 00-B9 Digital Input, Channel 16 (J5-P9)

NOTE: (J4-P2) is interpreted as Connector J4, Pin 2 on the Base ControlModule. * IMPORTANT: These Digital Inputs are defined as read only. If youdecide to write to these Inputs, unexpected results could occur.

Number ofDevice Function Address Digital Inputs CRC

Address Code Hi Lo Hi Lo Lo Hi01 02 00 AD 00 01 28 2B


01 02 01 01 60 48



91

Function 03 - Read Holding RegistersReads the binary content of holding registers (MODBUS 4x references) in the slave (CMCBase Control Module). For the CMC, these holding registers contain the Analog Outputvalues and Analog Alarm and Trip Setpoint values for all CMC inputs and outputs. Broadcastis not supported.

The CMC is primarily a 32-bit floating-point microprocessor controller. And, since MODBUSis designed to be a 16-bit system, the CMC supports two methods for determining the valuefor each holding register (This also applies to Input Registers.)

NOTE

Since MODBUS is a 16-bit system, the programmer must get two 16-bit numbers andcombine them into one 32-bit floating-point number.

The first method uses two 16-bit integers to represent the integer and fraction part of thevalue. The second method uses one 32-bit IEEE floating point number. (NOTE: For thosewho would like to only get the 16-bit integer value, this will work well for most inputs;however, the CMC has some inputs, like vibration, that are typically less than one.

Since the CMC has programmable analog and discrete inputs and outputs, the programmermust use the electrical schematic supplied with the contract to determine which functionname and units of measure are associated with each input and output.

Refer to the table below for MODBUS Absolute Addresses for each Holding Registersupported by the CMC-MODBUS Interface.




Signed16 Bit Exponent

Unsigned16 Bit Fraction

SignedIEEE 32-Bit Float

Holding Register Name - Read/WriteAbsoluteAddress(Decimal)

RelativeAddress

(hex)

AbsoluteAddress(Decimal)

RelativeAddress

(hex)


RelativeAddress

(hex)Analog Output, Channel 1 (J3-P1,3) 40053 00-34 40054 00-35 43053 0B-ECAnalog Output, Channel 2 (J3-P4,6) 40055 00-36 40056 00-37 43055 0B-EEAnalog Output, Channel 3 (J3-P7,9) 40057 00-38 40058 00-39 43057 0B-F0Analog Output, Channel 4 (J3-P10,12) 40059 00-3A 40060 00-3B 43059 0B-F2Analog Input, Channel 1 (J2-P1,3) - High Trip Setpoint 40061 00-3C 40062 00-3D 43061 0B-F4Analog Input, Channel 1 (J2-P1,3) - High Alarm Setpoint 40063 00-3E 40064 00-3F 43063 0B-F6Analog Input, Channel 1 (J2-P1,3) - Low Alarm Setpoint 40065 00-40 40066 00-41 43065 0B-F8Analog Input, Channel 1 (J2-P1,3) - Low Trip Setpoint 40067 00-42 40068 00-43 43067 0B-FAAnalog Input, Channel 2 (J2-P5,7) - High Trip Setpoint 40069 00-44 40070 00-45 43069 0B-FCAnalog Input, Channel 2 (J2-P5,7) - High Alarm Setpoint 40071 00-46 40072 00-47 43071 0B-FEAnalog Input, Channel 2 (J2-P5,7) - Low Alarm Setpoint 40073 00-48 40074 00-49 43073 0C-00Analog Input, Channel 2 (J2-P5,7) - Low Trip Setpoint 40075 00-4A 40076 00-4B 43075 0C-02Analog Input, Channel 3 (J1-P1) - High Trip Setpoint 40077 00-4C 40078 00-4D 43077 0C-04Analog Input, Channel 3 (J1-P1) - High Alarm Setpoint 40079 00-4E 40080 00-4F 43079 0C-06Analog Input, Channel 3 (J1-P1) - Low Alarm Setpoint 40081 00-50 40082 00-51 43081 0C-08Analog Input, Channel 3 (J1-P1) - Low Trip Setpoint 40083 00-52 40084 00-53 43083 0C-0AAnalog Input, Channel 4 (J1-P4) - High Trip Setpoint 40085 00-54 40086 00-55 43085 0C-0CAnalog Input, Channel 4 (J1-P4) - High Alarm Setpoint 40087 00-56 40088 00-57 43087 0C-0EAnalog Input, Channel 4 (J1-P4) - Low Alarm Setpoint 40089 00-58 40090 00-59 43089 0C-10Analog Input, Channel 4 (J1-P4) - Low Trip Setpoint 40091 00-5A 40092 00-5B 43091 0C-12Analog Input, Channel 5 (J1-P5) - High Trip Setpoint 40093 00-5C 40094 00-5D 43093 0C-14Analog Input, Channel 5 (J1-P5) - High Alarm Setpoint 40095 00-5E 40096 00-5F 43095 0C-16Analog Input, Channel 5 (J1-P5) - Low Alarm Setpoint 40097 00-60 40098 00-61 43097 0C-18Analog Input, Channel 5 (J1-P5) - Low Trip Setpoint 40099 00-62 40100 00-63 43099 0C-1AAnalog Input, Channel 6 (J1-P8) - High Trip Setpoint 40101 00-64 40102 00-65 43101 0C-1CAnalog Input, Channel 6 (J1-P8) - High Alarm Setpoint 40103 00-66 40104 00-67 43103 0C-1EAnalog Input, Channel 6 (J1-P8) - Low Alarm Setpoint 40105 00-68 40106 00-69 43105 0C-20Analog Input, Channel 6 (J1-P8) - Low Trip Setpoint 40107 00-6A 40108 00-6B 43107 0C-22Analog Input, Channel 7 (J1-P9) - High Trip Setpoint 40109 00-6C 40110 00-6D 43109 0C-24Analog Input, Channel 7 (J1-P9) - High Alarm Setpoint 40111 00-6E 40112 00-6F 43111 0C-26Analog Input, Channel 7 (J1-P9) - Low Alarm Setpoint 40113 00-70 40114 00-71 43113 0C-28Analog Input, Channel 7 (J1-P9) - Low Trip Setpoint 40115 00-72 40116 00-73 43115 0C-2AAnalog Input, Channel 8 (J1-P12) - High Trip Setpoint 40117 00-74 40118 00-75 43117 0C-2CAnalog Input, Channel 8 (J1-P12) - High Alarm Setpoint 40119 00-76 40120 00-77 43119 0C-2EAnalog Input, Channel 8 (J1-P12) - Low Alarm Setpoint 40121 00-78 40122 00-79 43121 0C-30Analog Input, Channel 8 (J1-P12) - Low Trip Setpoint 40123 00-7A 40124 00-7B 43123 0C-32Analog Input, Channel 9 (J1-P13) - High Trip Setpoint 40125 00-7C 40126 00-7D 43125 0C-34Analog Input, Channel 9 (J1-P13) - High Alarm Setpoint 40127 00-7E 40128 00-7F 43127 0C-36Analog Input, Channel 9 (J1-P13) - Low Alarm Setpoint 40129 00-80 40130 00-81 43129 0C-38Analog Input, Channel 9 (J1-P13) - Low Trip Setpoint 40131 00-82 40132 00-83 43131 0C-3AAnalog Input, Channel 10 (J1-P16) - High Trip Setpoint 40133 00-84 40134 00-85 43133 0C-3CAnalog Input, Channel 10 (J1-P16) - High Alarm Setpoint 40135 00-86 40136 00-87 43135 0C-3EAnalog Input, Channel 10 (J1-P16) - Low Alarm Setpoint 40137 00-88 40138 00-89 43137 0C-40Analog Input, Channel 10 (J1-P16) - Low Trip Setpoint 40139 00-8A 40140 00-8B 43139 0C-42Analog Input, Channel 11 (J1-P17) - High Trip Setpoint 40141 00-8C 40142 00-8D 43141 0C-44Analog Input, Channel 11 (J1-P17) - High Alarm Setpoint 40143 00-8E 40144 00-8F 43143 0C-46Analog Input, Channel 11 (J1-P17) - Low Alarm Setpoint 40145 00-90 40146 00-91 43145 0C-48



93

Analog Input, Channel 11 (J1-P17) - Low Trip Setpoint 40147 00-92 40148 00-93 43147 0C-4AAnalog Input, Channel 12 (J1-P20) - High Trip Setpoint 40149 00-94 40150 00-95 43149 0C-4CAnalog Input, Channel 12 (J1-P20) - High Alarm Setpoint 40151 00-96 40152 00-97 43151 0C-4EAnalog Input, Channel 12 (J1-P20) - Low Alarm Setpoint 40153 00-98 40154 00-99 43153 0C-50Analog Input, Channel 12 (J1-P20) - Low Trip Setpoint 40155 00-9A 40156 00-9B 43155 0C-52Analog Input, Channel 13 (J1-P21) - High Trip Setpoint 40157 00-9C 40158 00-9D 43157 0C-54Analog Input, Channel 13 (J1-P21) - High Alarm Setpoint 40159 00-9E 40160 00-9F 43159 0C-56Analog Input, Channel 13 (J1-P21) - Low Alarm Setpoint 40161 00-A0 40162 00-A1 43161 0C-58Analog Input, Channel 13 (J1-P21) - Low Trip Setpoint 40163 00-A2 40164 00-A3 43163 0C-5A








RelativeAddress

(hex)


RelativeAddress

(hex)


RelativeAddress

(hex)Analog Input, Channel 14 (J1-P24) - High Trip Setpoint 40165 00-A4 40166 00-A5 43165 0C-5CAnalog Input, Channel 14 (J1-P24) - High Alarm Setpoint 40167 00-A6 40168 00-A7 43167 0C-5EAnalog Input, Channel 14 (J1-P24) - Low Alarm Setpoint 40169 00-A8 40170 00-A9 43169 0C-60Analog Input, Channel 14 (J1-P24) - Low Trip Setpoint 40171 00-AA 40172 00-AB 43171 0C-62Analog Input, Channel 15 (J1-P25) - High Trip Setpoint 40173 00-AC 40174 00-AD 43173 0C-64Analog Input, Channel 15 (J1-P25) - High Alarm Setpoint 40175 00-AE 40176 00-AF 43175 0C-66Analog Input, Channel 15 (J1-P25) - Low Alarm Setpoint 40177 00-B0 40178 00-B1 43177 0C-68Analog Input, Channel 15 (J1-P25) - Low Trip Setpoint 40179 00-B2 40180 00-B3 43179 0C-6AAnalog Input, Channel 16 (J1-P28) - High Trip Setpoint 40181 00-B4 40182 00-B5 43181 0C-6CAnalog Input, Channel 16 (J1-P28) - High Alarm Setpoint 40183 00-B6 40184 00-B7 43183 0C-6EAnalog Input, Channel 16 (J1-P28) - Low Alarm Setpoint 40185 00-B8 40186 00-B9 43185 0C-70Analog Input, Channel 16 (J1-P28) - Low Trip Setpoint 40187 00-BA 40188 00-BB 43187 0C-72Analog Input, Channel 17 (J1-P29) - High Trip Setpoint 40189 00-BC 40190 00-BD 43189 0C-74Analog Input, Channel 17 (J1-P29) - High Alarm Setpoint 40191 00-BE 40192 00-BF 43191 0C-76Analog Input, Channel 17 (J1-P29) - Low Alarm Setpoint 40193 00-C0 40194 00-C1 43193 0C-78Analog Input, Channel 17 (J1-P29) - Low Trip Setpoint 40195 00-C2 40196 00-C3 43195 0C-7AAnalog Input, Channel 18 (J1-P32) - High Trip Setpoint 40197 00-C4 40198 00-C5 43197 0C-7CAnalog Input, Channel 18 (J1-P32) - High Alarm Setpoint 40199 00-C6 40200 00-C7 43199 0C-7EAnalog Input, Channel 18 (J1-P32) - Low Alarm Setpoint 40201 00-C8 40202 00-C9 43201 0C-80Analog Input, Channel 18 (J1-P32) - Low Trip Setpoint 40203 00-CA 40204 00-CB 43203 0C-82Analog Input, Channel 19 (J1-P33) - High Trip Setpoint 40205 00-CC 40206 00-CD 43205 0C-84Analog Input, Channel 19 (J1-P33) - High Alarm Setpoint 40207 00-CE 40208 00-CF 43207 0C-86Analog Input, Channel 19 (J1-P33) - Low Alarm Setpoint 40209 00-D0 40210 00-D1 43209 0C-88Analog Input, Channel 19 (J1-P33) - Low Trip Setpoint 40211 00-D2 40212 00-D3 43211 0C-8AAnalog Input, Channel 20 (J1-P36) - High Trip Setpoint 40213 00-D4 40214 00-D5 43213 0C-8CAnalog Input, Channel 20 (J1-P36) - High Alarm Setpoint 40215 00-D6 40216 00-D7 43215 0C-8EAnalog Input, Channel 20 (J1-P36) - Low Alarm Setpoint 40217 00-D8 40218 00-D9 43217 0C-90Analog Input, Channel 20 (J1-P36) - Low Trip Setpoint 40219 00-DA 40220 00-DB 43219 0C-92Analog Input, Channel 21 (J1-P37) - High Trip Setpoint 40221 00-DC 40222 00-DD 43221 0C-94Analog Input, Channel 21 (J1-P37) - High Alarm Setpoint 40223 00-DE 40224 00-DF 43223 0C-96Analog Input, Channel 21 (J1-P37) - Low Alarm Setpoint 40225 00-E0 40226 00-E1 43225 0C-98Analog Input, Channel 21 (J1-P37) - Low Trip Setpoint 40227 00-E2 40228 00-E3 43227 0C-9AAnalog Input, Channel 22 (J1-P40) - High Trip Setpoint 40229 00-E4 40230 00-E5 43229 0C-9CAnalog Input, Channel 22 (J1-P40) - High Alarm Setpoint 40231 00-E6 40232 00-E7 43231 0C-9EAnalog Input, Channel 22 (J1-P40) - Low Alarm Setpoint 40233 00-E8 40234 00-E9 43233 0C-A0Analog Input, Channel 22 (J1-P40) - Low Trip Setpoint 40235 00-EA 40236 00-EB 43235 0C-A2Analog Input, Channel 23 (J1-P41) - High Trip Setpoint 40237 00-EC 40238 00-ED 43237 0C-A4Analog Input, Channel 23 (J1-P41) - High Alarm Setpoint 40239 00-EE 40240 00-EF 43239 0C-A6Analog Input, Channel 23 (J1-P41) - Low Alarm Setpoint 40241 00-F0 40242 00-F1 43241 0C-A8Analog Input, Channel 23 (J1-P41) - Low Trip Setpoint 40243 00-F2 40244 00-F3 43243 0C-AAMotor Current 40267 01-0A 40268 01-0B 43267 0C-C2User Pressure Setpoint 40269 01-0C 40270 01-0D 43269 0C-C4MinLoad (Throttle Limit, TL) 40271 01-0E 40272 01-0F 43271 0C-C6MaxLoad (High Load Limit, HLL) 40273 01-10 40274 01-11 43273 0C-C8Autodual Reload Percent 40275 01-12 40276 01-13 43275 0C-CAAutodual Unload Point 40277 01-14 40278 01-15 43277 0C-CCAutodual Unload Timer 40279 01-16 40280 01-17 43279 0C-CEPressure Setpoint Ramp Rate 40281 01-18 40282 01-19 43281 0C-D0



95

Inlet Valve Unload Position 40283 01-1A 40284 01-1B 43283 0C-D2Start Timer 40285 01-1C 40286 01-1D 43285 0C-D4CT Ratio 40287 01-1E 40288 01-1F 43287 0C-D6Power On Hours 40297 01-28 40298 01-29 43297 0C-E0Running Hours 40299 01-2A 40300 01-2B 43299 0C-E2Loaded Hours 40301 01-2C 40302 01-2D 43301 0C-E4Number of Starts 40303 01-2E 40304 01-2F 43303 0C-E6








RelativeAddress

(hex)


RelativeAddress

(hex)


RelativeAddress

(hex)Inlet Valve, MaxLoad, Proportional Constant 40313 01-38 40314 01-39 43313 0C-F0Inlet Valve, MaxLoad, Integral Constant 40315 01-3A 40316 01-3B 43315 0C-F2Inlet Valve, MaxLoad, Derivative Constant 40317 01-3C 40318 01-3D 43317 0C-F4Inlet Valve, MinLoad, Proportional Constant 40319 01-3E 40320 01-3F 43319 0C-F6Inlet Valve, MinLoad, Integral Constant 40321 01-40 40322 01-41 43321 0C-F8Inlet Valve, MinLoad, Derivative Constant 40323 01-42 40324 01-43 43323 0C-FAInlet Valve, Pressure, Proportional Constant 40325 01-44 40326 01-45 43325 0C-FCInlet Valve, Pressure, Integral Constant 40327 01-46 40328 01-47 43327 0C-FEInlet Valve, Pressure, Derivative Constant 40329 01-48 40330 01-49 43329 0D-00Bypass Valve, Pressure, Proportional Constant 40331 01-4A 40332 01-4B 43331 0D-02Bypass Valve, Pressure, Integral Constant 40333 01-4C 40334 01-4D 43333 0D-04Bypass Valve, Pressure, Derivative Constant 40335 01-4E 40336 01-4F 43335 0D-06Compressor Control Mode; 1=Modulate, 2=Autodual 40339 01-52 40340 01-53 43339 0D-0ANOTE: (J1-P1) is interpreted as Connector J1, Pin 1 on the Base Control Module.

Example: See example for Function 04.

Function 04 - Read Input RegistersReads the binary content of input registers (MODBUS 3x references) in the slave (CMCBase Control Module). For the CMC, these input registers refer to the Analog Input values.Broadcast is not supported.

The CMC is primarily a 32-bit floating-point microprocessor controller. And, since MODBUSis designed to be a 16-bit system, the CMC supports two methods for determining the valuefor each holding register. (This also applies to Input Registers.) The first method uses two16-bit integers to represent the integer and fraction part of the value. The second methoduses one 32-bit IEEE floating point number.

NOTE

Since MODBUS is a 16-bit system, the programmer must get two 16-bit numbers andcombine them into one 32-bit floating-point number.

For those who would like to only get the 16-bit integer value, this will work well for mostinputs; however, the CMC has some inputs, like vibration, that are typically less than one.



97

Example: Read Single Channel 16-Bit Integer and FractionAfter reviewing the Electrical Schematic for your compressor, you determine that the analoginput for System Pressure is located on J1-P1 (Channel 3). From the table above, theAbsolute Address is decimal 30007 (Relative Address is hexadecimal 0006) for the input inquestion. Therefore, to read the 16 Bit Integer and 16 Bit Fraction for System Pressure thefollowing command is issued (the following data are presented in hexadecimal format):


Signed16-Bit Integer

Unsigned16-Bit Fraction


Input Register Name - Read Only*AbsoluteAddress(Decimal)

RelativeAddress

(hex)


RelativeAddress

(hex)


RelativeAddress

(hex)Analog Input, Channel 1 (J2-P1,3) 30003 00-02 30004 00-03 33003 0B-BAAnalog Input, Channel 2 (J2-P5,7) 30005 00-04 30006 00-05 33005 0B-BCAnalog Input, Channel 3 (J1-P1) 30007 00-06 30008 00-07 33007 0B-BEAnalog Input, Channel 4 (J1-P4) 30009 00-08 30010 00-09 33009 0B-C0Analog Input, Channel 5 (J1-P5) 30011 00-0A 30012 00-0B 33011 0B-C2Analog Input, Channel 6 (J1-P8) 30013 00-0C 30014 00-0D 33013 0B-C4Analog Input, Channel 7 (J1-P9) 30015 00-0E 30016 00-0F 33015 0B-C6Analog Input, Channel 8 (J1-P12) 30017 00-10 30018 00-11 33017 0B-C8Analog Input, Channel 9 (J1-P13) 30019 00-12 30020 00-13 33019 0B-CAAnalog Input, Channel 10 (J1-P16) 30021 00-14 30022 00-15 33021 0B-CCAnalog Input, Channel 11 (J1-P17) 30023 00-16 30024 00-17 33023 0B-CEAnalog Input, Channel 12 (J1-P20) 30025 00-18 30026 00-19 33025 0B-D0Analog Input, Channel 13 (J1-P21) 30027 00-1A 30028 00-1B 33027 0B-D2Analog Input, Channel 14 (J1-P24) 30029 00-1C 30030 00-1D 33029 0B-D4Analog Input, Channel 15 (J1-P25) 30031 00-1E 30032 00-1F 33031 0B-D6Analog Input, Channel 16 (J1-P28) 30033 00-20 30034 00-21 33033 0B-D8Analog Input, Channel 17 (J1-P29) 30035 00-22 30036 00-23 33035 0B-DAAnalog Input, Channel 18 (J1-P32) 30037 00-24 30038 00-25 33037 0B-DCAnalog Input, Channel 19 (J1-P33) 30039 00-26 30040 00-27 33039 0B-DEAnalog Input, Channel 20 (J1-P36) 30041 00-28 30042 00-29 33041 0B-E0Analog Input, Channel 21 (J1-P37) 30043 00-2A 30044 00-2B 33043 0B-E2Analog Input, Channel 22 (J1-P40) 30045 00-2C 30046 00-2D 33045 0B-E4Analog Input, Channel 23 (J1-P41) 30047 00-2E 30048 00-2F 33047 0B-E6CT Input (J9-P1,2) 30049 00-30 30050 00-31 33049 0B-E8NOTE: (J1-P1) is interpreted as Connector J1, Pin 1 on the Base Control Module. * IMPORTANT: These Input Registers are defined asread only. If you decide to write to these Input Registers, unexpected results could occur.

Number ofDevice Function Address Registers CRC

Address Code Hi Lo Hi Lo Lo Hi01 04 00 06 00 02 91 CA

DataDevice Function Byte Reg-1 Reg-2 CRC

Address Code Count Hi Lo Hi Lo Lo Hi01 04 04 00 64 13 4E 37 5F




Register 1 is the Integer portion of the System Pressure or (0064h, 100 decimal). Register 2is the Fraction portion of the System Pressure or (134Eh, 4942 decimal). Each fraction hasa range between 0 and 9999. So the System Pressure, expressed as a floating pointnumber is 100.4942 psi.

Example: Read Single Channel IEEE 32-Bit Floating Point NumberTo continue with the example, when you decide to get the System Pressure as an IEEE 32Bit floating point number you must issue the following command:


So the System Pressure, expressed as a floating point number is 110.4155731201 psi.IEEE floating point numbers are represented in 32 bits as shown below.

Convert hexadecimal registers 1 and 2 (Reg-1, Reg-2) into decimal values ...


Address Code Hi Lo Hi Lo Lo Hi01 04 0B BE 00 02 13 CB

DataDevice Function Byte Reg-1 Reg-2 CRC

Address Code Count Hi Lo Hi Lo Lo Hi01 04 04 42 DC D4 C6 F1 54

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

exponent mantissa

sign

Register Byte Symbol Hex Decimal1 Hi R1HB 42 661 Lo R1LB DC 2202 Hi R2HB D4 2122 Lo R2LB C6 198



99

Determine the sign (positive = 0 or negative = 1) ...

Sign = (R1HB And 128) / 128, where And is defined as a bit-wise And

Sign = (66 And 128) / 128 = 0

Determine the exponent ...

Exponent = ((R1HB And 127) ∗ 2) + INT(R1LB / 128), where INT is defined as INTEGER

Exponent = ((66 And 127) ∗ 2) + INT(220/128) = 133

Determine the mantissa...

Mantissa = ((((R1LB And 127) ∗ 256) + R2HB) ∗ 256) + R2LB

Mantissa = ((((220 And 127) ∗ 256) + 212) ∗ 256) + 198 = 6083782

Putting the 32 bit IEEE value together...

Value = (-1sign) ∗ (2(exponent - 127)) ∗ ((Mantissa ∗ 2-23) + 1)

Value = (-10) ∗ (2(133- 127)) ∗ ((6083782 ∗ 2-23) + 1) = 110.4155731201

NOTE

When Sign = Exponent = Mantissa = 0, Value = 0. This is a special case for the aboveequation.

Example: Read Multiple ChannelsThe procedure for reading multiple channels is the same as reading a single channel withthe exception of requesting more data. NOTE: You must read a contiguous group ofregisters (channels) for a single command.

Function 05 - Force Single CoilForces a single coil (MODBUS 0x references) to either ON or OFF. When broadcast, thefunction forces the same coil reference in all attached slaves. Refer to the table below forMODBUS Absolute Addresses for each coil supported by the CMC-MODBUS Interface.

NOTE

This function will override the CMC’s current state. The forced state will remain validuntil the CMC next solves the coil. The coil will remain forced if it is not programmed inthe CMC logic.




CAUTION

For all of the following Remote Coils, the compressor’s REMOTECOMMUNICATIONS DISABLED/ENABLED selector switch must be in the ENABLEDposition for these commands to execute. When DISABLED, the CMC ignores (there isno exception response) these coils being forced ON or OFF.

Example: Forcing a CoilFor all MODBUS devices, a value of FF 00 hex requests the coil to be ON. A value of 00 00requests it to be OFF. All other values are illegal and will not affect the coil. NOTE: For theCMC, forcing the above listed coils OFF is not meaningful because the default state of eachof the above coils is OFF. When using these commands, they should be sent once(momentary) and the CMC will execute the commands. To remotely reset the compressor,the following command is issued:

The response from this command is identical to the command sent:

Function 06 - Preset Single RegisterPresets a value into a single holding register (MODBUS 4x reference). When broadcast, thefunction presets the same register reference in all attached slaves. Refer to the table for theHolding Register list for the MODBUS Absolute Addresses supported by the CMC-MODBUSInterface.

AbsoluteAddress(decimal)

RelativeAddress

(hex)Coil Name - Write Only

00221 00-DC Remote Horn Silence(Acknowledge)

00222 00-DD Remote Reset00223 00-DE Remote Load00224 00-DF Remote Unload00225 00-E0 Remote Start00226 00-E1 Remote Stop

ForcedDevice Function Address Data CRC

Address Code Hi Lo Hi Lo Lo Hi01 05 00 DD FF 00 1C 00


Address Code Hi Lo Hi Lo Lo Hi01 05 00 DD FF 00 1C 00



101

NOTE

This function will override the CMC’s current state. The preset value will remain validin the register until the CMC logic next solves the register contents. The register'svalue will remain if it is not programmed in the controller's logic.

CAUTION

This function can only set a single 16-bit holding register. Since the CMCoperates with 32-bit values, you must use Function 16 (10 Hex) - Preset MultipleRegisters for setting the 32-bit IEEE register values. Also, you may not set the 16-bitfraction without its 16-bit integer. Therefore, you must use the Preset MultipleRegisters function to send this 32-bit pair. See the examples that follow forFunction 16.

CAUTION

The position of the REMOTE COMMUNICATIONS DISABLED/ENABLEDselector switch is NOT considered when forcing coils or writing registers to the CMC.Reads and Writes are always enabled. Repeatedly writing a value to a register orforcing a coil without regard to the position of the switch can effectively disable a localwrite. Please use caution when writing registers or forcing coils.

Example: Presetting a Single Register (16-bit) IntegerTo change the integer value for the User Pressure Setpoint (absolute address 40269,relative address 01-0C) to 100 (00-64 hex) psi, send the following command...

The response from this command is identical to the command sent:

Function 15 (0F Hex) - Force Multiple CoilsForces each coil (MODBUS 0x reference) in a series of contiguous coils to either ON orOFF. When broadcast, the function forces the same coil references in all attached slaves

RegisterDevice Function Address Value CRC

Address Code Hi Lo Hi Lo Lo Hi01 06 01 0C 00 64 49 DE

RegisterDevice Function Address Value CRC

Address Code Hi Lo Hi Lo Lo Hi01 06 01 0C 00 64 49 DE




(CMC Base Control Modules). Refer to the table for the Coil list for the MODBUS AbsoluteAddresses supported by the CMC-MODBUS Interface.

NOTE

This function will override the CMC’s current state. The forced state will remain validuntil the CMC next solves the coil. The coil will remain forced if it is not programmed inthe controller's logic.

CAUTION


Example: Forcing Multiple CoilsTo force a reset (absolute address 00222, relative address DD) and start (absolute address00225, relative address E0) of the compressor the following command is sent...

The number of contiguous coils is four (00225, 00224, 00223 and 00222). The number ofdata bytes is one because we can set up to eight coils in a single byte. The coil data is ninebecause we want to set the first bit and fourth bit in the byte (0000-1001, the bytes arenumbered right to left). All bits not used are padded with zero.

The response from this command is similar to the command sent except that the number ofdata bytes and the coil data themselves are not echoed:

Function 16 (10 Hex) - Preset Multiple RegistersPresets values into a sequence of contiguous holding registers (MODBUS 4x references).When broadcast, the function presets the same register references in all attached slaves

Device Function

AddressNumber of

CoilsNumbe

rof Data

CoilData CRC

Address Code Hi Lo Hi Lo Bytes Lo Lo Hi01 0F 00 DD 00 04 01 09 12 83

Number ofDevice Functio

nAddress Coils CRC

Address Code Hi Lo Hi Lo Lo Hi01 0F 00 DD 00 04 C4 32



103

(CMC Base Control Modules). Refer to the table for the Input Register list for the MODBUSAbsolute Addresses supported by the CMC-MODBUS Interface.

NOTE

This function will override the CMC’s current state. The forced state will remain validuntil the CMC next solves the register. The register will remain forced if it is notprogrammed in the controller's logic.

CAUTION


Example: Presetting Holding Registers for 32-bit ValuesThe difficulty in setting 32-bit values is determining the four data bytes for the number youwant to send. The process required is...

1. Determine the sign (positive = 0 or negative = 1). This is the first bit.

2. Divide the decimal value by 2 until the result is less than 2, but greater than 1. Count thenumber of iterations required. Add 127 to the number of iterations. This result is theexponent. Convert this result to binary. These are the next eight bits.

3. From the result obtained from step 2, subtract 1. Then, multiply this result by 2. If theresult is less than 1, then the value of the first mantissa bit is 0. Otherwise, themantissa bit is 1. If the result is greater than or equal to 1, then subtract 1 from theresult and proceed with step 3 until the result is 0 or you have gone through thisprocess 23 times.

4. Combine all 32 bits from the steps above and convert this value to hexadecimal. These32 bits are the 4 hexadecimal data bytes needed for the command.

As an example, we will start with the decimal value of105.4.

1. Since this is a positive number, the first bit is 0.

2. Determine the exponent bits by ...

Iteration

Decimal Result

1 105.40000 / 2 = 52.7000002 52.70000 / 2 = 26.3500003 26.35000 / 2 = 13.1750004 13.17500 / 2 = 6.5875005 6.58750 / 2 = 3.2937506 3.29375 / 2 = 1.646875




It took us six iterations to get the result to a number that is less than two and greater than orequal to one. Now, we must add 127 for an exponent of133. Converting this to binary, the next eight bits arerepresented as 10000101.

3. Determine the mantissa bits by

From the table at right, 0100101100110011001100represent the next 23 bits.

4. Combining the bits in sign, exponent and thenmantissa order ...

0100-0010-1101-0010-1100-1100-1100-1100

This converts to 42-D2-CC-CC in hexadecimal.

To change the holding registers for user pressuresetpoint (for 32 bit IEEE floating point numbers theabsolute address is 43269, relative address 0C-C4) to105.4, issue the following command...

The response from this command is similar to the command sent except that the number ofdata bytes and the data bytes themselves are not echoed:

NOTE

Sending 32 bit values are typically not necessary. Sending the data as a 16 bit integeronly or a 16 bit integer and 16 bit fraction will satisfy most requirements. Somesystems have 32 bit capability built directly into their products. We have provided thisfeature for those systems.

Iteration Decimal Operation

Result Bit

1 1.646875 - 1 * 2 = 1.29375 12 1.29375 - 1 * 2 = 0.5875 03 0.5875 * 2 = 1.175 14 1.175 - 1 * 2 = 0.35 05 0.35 * 2 = 0.7 06 0.7 * 2 = 1.4 17 1.4 - 1 * 2 = 0.8 08 0.8 * 2 = 1.6 19 1.6 - 1 * 2 = 1.2 110 1.2 - 1 * 2 = 0.4 011 0.4 * 2 = 0.8 012 0.8 * 2 = 1.6 113 1.6 - 1 * 2 = 1.2 114 1.2 - 1 * 2 = 0.4 015 0.4 * 2 = 0.8 016 0.8 * 2 = 1.6 117 1.6 - 1 * 2 = 1.2 118 1.2 - 1 * 2 = 0.4 019 0.4 * 2 = 0.8 020 0.8 * 2 = 1.6 121 1.6 - 1 * 2 = 1.2 122 1.2 - 1 * 2 = 0.4 023 0.4 * 2 = 0.8 0

Device Function

AddressNumber ofRegisters

Number

of Data

Data Bytesfor Register

#1


#2CRC

Address Code Hi Lo Hi Lo Bytes Hi Lo Hi Lo Lo Hi01 10 0C C4 00 02 04 42 D2 CC CC 4A 18


Address Code Hi Lo Hi Lo Lo Hi01 10 0C C4 00 02 03 65



105

CAUTION


Example: Presetting a 16-bit Integer and 16-bit Fraction Holding RegisterChange the integer and fraction value for the user pressure setpoint (absolute address40269, relative address 01-0C) to 110.5 psi. The integer portion of the number 110 (00-6Ehex) is placed at address 40269 and the fraction 0.5 is converted to 5000 (13-88 hex) and isplaced at address 40270 (or the second data byte). To change the register, issue thefollowing command...

The response from this command is similar to the command sent except that the number ofdata bytes and the data bytes themselves are not echoed:

Exception ResponsesExcept for broadcast messages, when a master device sends a query to a slave device itexpects a normal response, in all other cases a time out or exception response is returned.The four possible responses to a the master's query are:

• If the slave device receives the query without a communication error, and can handle thequery normally, it returns a normal response.

• If the slave does not receive the query due to a communication error, no response isreturned. The master program will eventually process a time-out condition for the query.

• If the slave receives the query, but detects a communication error (parity, or CRC), noresponse is returned. The master program will eventually process a time-out conditionfor the query.

• If the slave receives the query without a communication error, but cannot handle it (forexample, if the request is to read a nonexistent coil or register), the slave will return anexception response informing the master of the nature of the error.

The exception response message has two fields that differentiate it from a normalresponse:

Device Function

AddressNumber ofRegisters

Number

of Data


#1


#2CRC

Address Code Hi Lo Hi Lo Bytes Hi Lo Hi Lo Lo Hi01 10 01 0C 00 02 04 00 6E 13 88 92 E1


Address Code Hi Lo Hi Lo Lo Hi01 10 01 0C 00 02 80 37




Function Code FieldFor a normal response, the UCM echoes the function code of the original query in thefunction code field of the response. All function codes have their most significant bits set tozero; therefore, the values are always below 80 hexadecimal. When an exception responseoccurs, the UCM sets the most significant bit of the function code to 1. This makes thefunction code value in an exception response exactly 80 hexadecimal higher than the valuewould be for a normal response.

With the function code's most significant bit set, the application program can recognize anexception response and can examine the data field for the exception code.

Data FieldFor a normal response, the UCM will return information in the data field (depending upon thequery message sent). For an exception response, the UCM returns an exception code in thedata field. This defines the UCM’s condition that caused the exception.

Exception Codes Supported by the CMC Microcontroller

Most Significant Bit Least Significant Bit7 6 5 4 3 2 1 01 0 0 0 0 0 0 0



107

Maximum Query / Response ParametersThe listing below shows the maximum amount of data that the CMC Microcontroller canreturn in a single slave response from a valid MODBUS command.

Code

Name Meaning

01 Illegal Function The function code received in the query is not an allowable action for the slave. This exception code happenswhen:

(1) the function code is other than 1, 2, 3, 4, 5, 6, 15 or 16(2) a message has the incorrect number of bytes for the function specified

02 Illegal Data Address The data address received in the query is not an allowable address for the slave. This exception code happenswhen:

(1) the address is not programmed into the Base Control Module (BCM)(2) the address is outside of the ranges

(a) 00001-00512 for coils(b) 10001-10512 for discrete inputs(c) 30001-31024 for integer and fractional analog inputs(d) 33001-34024 for floating point analog inputs(e) 40001-41024 for integer and fractional input registers(f) 43001-44024 for floating point analog input registers

03 Illegal Data Value A value contained in the query data field is not an allowable value for the slave. This exception code happenswhen:

(1) the number of coils, discrete inputs, registers or analog inputs is equal to zero(2) request for more than the maximum number of parameters(3) the force single coil command, Function 05, is issued and the value is other than FF00 or 0000(4) the force multiple coil command, Function 15, is issued and the number of bytes does not equal the numberof bits to set(5) the preset single register command, Function 6, and preset multiple registers commands, Function 16, isissued and the starting address is not even, the number of registers specified does not correspond to thenumber of bytes in the message, the integer part of the number is outside the range –32768 to +32767, thefractional part of the number is outside of the range 0-9999, or the value is not a valid 32 bit IEEE floating pointnumber

04 Slave DeviceFailure

An unrecoverable error occurred while the slave was attempting to perform the requested action. This exceptioncode happens when:

(1) no response from the Base Control Module (BCM) since 800 milliseconds from the time the message wassent … BCM not wired properly, BCM hardware problem or BCM Module ID not equal to one(2) when there is an unexpected response from the BCM … this is the default exception response

Function MaximumDec Hex Description Parameters01 01 Read Coil Status 512 coils02 02 Read Input Status 512 inputs03 03 Read Holding Registers 64 registers04 04 Read Input Registers 64 registers05 05 Force Single Coil 1 coil06 06 Preset Single Register 1 register15 0F Force Multiple Coils 512 coils16 10 Preset Multiple

Registers64 registers




CMC DataThe CMC Microcontroller supports several data types. They are coil, integer, fraction andfloating point.

• Coil - 1 bit, 1 means True or Active, 0 means False or Not Active.

• Integer - 16 bit signed integer, –32768 to +32767.

• Fraction - 16 bit unsigned integer, 0 – 9999, represents the decimal (fractional) part ofthe number (1 represents 0.0001, 10 represents 0.0010, 100 represents 0.0100 and1000 represents 0.1000).

• Floating Point - 32 bit IEEE number (requires reading two registers to get full number).

For example if the System Pressure input is located on Channel 3 (address 30007) and thevalue of the pressure is 100.5 then:

Address 30007 contains 100

Address 30008 contains 5000

Address 33007 contains the high 16 bits of the IEEE value for 100.5

Address 33008 contains the low 16 bits of IEEE value for 100.5

Additionally, the type of data in a location determines the commands that can be used toaccess the data. For the previous example of System Pressure addresses 00007, 03007,10007, 13007, 40007 and 43023 return errors because coil, input status and holding registercommands cannot read input register data.

Scaling and Units of MeasureThe MODBUS data are scaled in English engineering units. All pressures are in psi,temperatures in degrees F, vibrations in mils, and current in amps. For example, when theCMC Operator User Interface displays the system pressure as 7.73 kg/cm2, the value forsystem pressure obtained through MODBUS communications is 110 psi.

Communication ParametersConfiguration of the communication speed (baud rate), parity, number of data bits andnumber of stop bits is available through the Ingersoll-Rand Service Tool and will be providedby a certified Ingersoll-Rand Service Representative.



109

The CMC-DF1 InterfaceIntroduction

Customers may want to communicate to the CMC control systems for remote compressorcontrol and monitoring through their Allen-Bradley data highway plus (DH+) network. AddingAllen-Bradley DF1 protocol to the UCM module allows our customers to incorporate ourcompressors into their plant-wide Allen-Bradley PLC control system. This communicationcapability also provides for flexibility in the customer's compressed air operation throughremote start, stop, and data gathering for preventative maintenance.

The customer or his representative must write system software to suit his individual needsfor remote control and monitoring. Since the customer writes this interface, the system canbe as flexible as the customer desires.

One avenue for communicating with the CMC is via DF1 protocol over a full duplex RS-422link. This requires an Allen-Bradley interface module 1770-KF2 to link our intelligent RS-422A asynchronous device, Universal Communication Module (UCM), to the Allen-BradleyDH+ network.

The CMC Microcontroller can communicate with other devices over a variety ofcommunication standards. Supported standards, or protocols, include RS-232, IRBUS(Ingersoll-Rand Proprietary), Modicon’s MODBUS, and Allen-Bradley DF1. The built-in portsof the CMC’s Universal Communication Module access communications. This UCM-DF1Interface defines the message structure that a CMC Microcontroller uses to exist on a DH+network. This interface will allow the DH+ network to gather information and control thecompressor.

The information presented in these sections that follow do not include the Allen-Bradley DF1protocol details. Detailed information can be obtained from “Allen-Bradley Publication 1770-6.5.117 - October 1996” - DF1 Protocol and Command Set Reference Manual and “DataHighway or Data Highway Plus Asynchronous (RS-232-C or RS-422-A) Interface Module(Cat. No. 1770-KF2) User’s Manual”.

A DH+ link implements peer-to-peer communication with a token-passing scheme to rotatemastership among the nodes connected to that link. In order to communicate over Allen-Bradley DH+ network, an Allen-Bradley 1770-KF2 interface module must be used. The1770-KF2 always acts as one node on the DH+ network, which translates DH+ messagesto DF1 format, and passes these messages on to the UCM on the RS-422A asynchronousend, or vice versa.

The following is a picture of 1770-KF2:




Full-Duplex ProtocolThe UCM-DF1 interface only supports the point-to-point full-duplex DF1 protocol, which islike a two-lane bridge; traffic can travel in both directions at one time. Full-duplex protocolalso provides higher performance applications to get the highest possible throughput.

DF1 Full-Duplex Protocol Message FramesThe following table shows the general format of a DF1 full-duplex message frame. Thecontrol symbols DLE STX bytes are sender symbols indicating the start of a messageframe. The control symbols DLE ETX BCC (CRC) bytes are sender symbols thatterminates a message frame. The bytes comprised in the command data field vary fromcommand to command.

NOTE

The standard definitions of the control characters used by DF1 full-duplex protocol arelisted below:

Abbreviation Hexadecimal ValueSTX 02ETX 03ENQ 05ACK 06DLE 10NAK 0F

DF1 Device AddressConfiguration of the DF1 device address is available through the Ingersoll-Rand UCM-Wizard Tool and will be configured by a certified Ingersoll-Rand Service Representative.

CAUTION

The UCM must be configured to have the same node address as 1770-KF2interface module. Otherwise, the DF1 messages will not be relayed to the IRBUS portof the UCM.

Destination (DST) ByteThis byte indicates the destination node address for the message. For a commandmessage, it will be the address of the 1770-KF2 module. The UCM must have the sameaddress as the 1770-KF2, which can be configured using the Ingersoll-Rand UCM-wizardsoftware.

DLE STX DST SRC CMD STS TNS Command Data DLE ETX BCC(CRC)



111

Source (SRC) ByteThis byte indicates the source node address of the message. If the command is initiatedfrom an Allen-Bradley PLC, the SRC byte will be the address of the processor module.

Command (CMD) and Function (FNC) BytesThe CMD byte defines the command type. The FNC byte defines the specific function underthat command type. These bytes together define the activity being performed by thecommand message at the destination node. The message format depends on the CMD andFNC values.

CMD Byte

Bit: 7 6 5 4 3 2 1 00 0:Command msg

1:Reply msg0: normal priority(for DH+)1: high priority(only applies to DH link)

0 Command code

From the figure above, the CMD byte of a reply message for DH+ network is always 40hORed with the CMD byte of its original command message.

Status (STS) Byte - Status Error CodeBit: 7 6 5 4 3 2 1 0

Remote Error Nibble Local Error Nibble

Bits 7, 6, 5, and 4 are used to report remote errors - errors that occur when the commandexecutor at the destination node tries to execute the command message. Bits 3, 2, 1, and 0are used to report local errors - errors found by the local source node and code 09h through0Fh are not used. The UCM-DF1 driver uses mainly the higher nibble to report errors occurin CMC. A special error code with non-zero local error nibble, 3Fh, is used to report errorscaused by illegal CMC data table address or count. The maximum number of data tableentries allowed to be read or set for CMC is 16 currently. If a read command requests morethan 16 data items from CMC, an exception response of 3Fh will be returned.

Following is a list of status error code supported by the UCM-DF1 driver:

Transaction (TNS) BytesThe two TNS bytes contain a unique 16-bit transaction identifier. Generate this number bymaintaining a 16-bit counter. Increment the counter each time your command initiatorcreates a new message, and store the counter value in the two TNS bytes of the newmessage. You must use only one TNS counter in a multi-tasking environment.

If the command initiator is an Allen-Bradley PLC, the PLC will maintain the counter internally.The reply message should have the same TNS value as the original command message.The UCM-DF1 driver copies the original TNS field of the command message into the TNSfield of the corresponding reply message.

BCC (Block Check Character) and CRC (Cyclic Redundancy Check)At the end of each DF1 command message, there is a one-byte BCC field, or a two-byteCRC field for error checking. These bytes allow you to verify the accuracy of each messageframe transmission. SW-1 of 1770-KF2 module allows you to select BCC or CRC error




checking for the command messages sent to CMC. The Ingersoll-Rand UCM-wizardsoftware allows you to configure BCC or CRC error checking for the UCM-DF1 driver, whichneeds to be the same error checking method as 1770-KF2.

BCC (One Byte)The BCC field contains the 2’s compliment of the 8-bit sum of all data bytes between DLESTX and DLE ETX BCC control characters. BCC provides a medium level of data security.It cannot detect either the transposition of bytes during transmission nor the insertion ordeletion of the value zero within a message frame.

Another way to quickly determine a BCC value, add up the hex values of all data bytesbetween DLE STX and DLE ETX BCC in the message frame. If the total is greater than100h, drop the most significant digit, and then subtract the result from 100h. This gives youthe BCC.

CRC (Two Bytes)This provides a higher level of data security than BCC but is more difficult to implement. Allthe data bytes between DLE STX and DLE ETX CRC plus the ETX byte are used tocalculate the CRC value.

The following explains how to calculate the CRC value:

• Before starting the calculation, a 16-bit register used to store the CRC value is clearedto be zero.

• As a byte is fetched from the data buffer, it is XORed (least-significant bit to the right)with the right eight bits of the CRC register.

• The result is placed in the right eight bits of the CRC register.

• Inserting 0s on the left then shifts the 16-bit CRC Register right eight times. Each time a1 is shifted out on the right, the CRC register is XORed with a 16-bit constant A0-01h.

• As each additional byte is fetched, it is included in the value in the register the sameway.

• After the ETX byte transmitted is also included in the calculation, the CRC calculation iscomplete. The 16-bit CRC value is transmitted low byte first then high byte.

Comparing the calculated BCC/CRC bytes with the received BCC/CRC bytes alwaysvalidates the DF1 messages received by UCM.

CAUTION

To transmit the data value of 10 hex, you must use the data symbol DLE DLE(double-stuffing DLEs). However, only one of these DLE bytes is included in theBCC/CRC calculation. However, if your BCC check sum is 10 hex, send it as DLEand not DLE DLE.

The rest of this section explains the meaning of the data bytes between DLE STX and DLEETX BCC/CRC control characters.



113

Usually, a command message stripping off the control characters has the following format,

DST SRC CMD STS TNS command specific data packet

a reply message to a read command has the format below,

SRC DST CMD STS TNS command specific data packet

a reply message to a write command has the following format,

SRC DST CMD STS TNS

The DST and SRC bytes of a reply message are formed by interchanging the DST andSRC bytes of the corresponding command message. The combination of SRC, CMD, andTNS bytes uniquely identifies every message packet. If all fields are the same, the messageis considered to be a duplicate. The UCM-DF1 driver does not detect duplicate messages.

Data AddressingThe CMC is primarily a 32-bit floating-point microprocessor controller. We support twomethods for determining the analog data value. These methods are two 16-bit integersrepresenting the integer and fraction part of the number and one 32-bit IEEE floating pointnumber. (NOTE: If you use the 16-bit system, you must get two 16-bit numbers andcombine them into one 32-bit floating point number.) The UCM-DF1 interface can preparedata as either two 16-bit integers or one 32-bit floating point number with respect to thereceived DF1 command. The Allen-Bradley PLC floating point format is a subset of IEEESTD 754-1985.

Accessing data from the CMC via DF1 interface emulates accessing data from a PLC5 orSLC5/04. In SLC 5/04, each data file can hold up to 256 data elements (element number: 0-255) and the file number has to be in the same range (0-255). The UCM-DF1 addressingscheme uses this file/element structure and complies with the SLC5/04’s limits on filenumber and element number. Please see next section for details.

A DF1 command initiator is a device on the DH+ network that initiates the query or setcommands to the CMC. It can be an Allen-Bradley PLC or other device that cansend/receive a PLC5 Typed Read (Write) or SLC Typed Logical Read (Write)command/response.

CMC as PLC5As to treating CMC as a PLC5, the command initiator can issue a PLC5 Typed Read (Write)command to the CMC. Please see the section on Supported Functions for detailedmessage format.

For a PLC5 Typed Write command, the data can be sent as either two 16-bit integers orone 32-bit floating point. If a PLC5 or SLC5/04 issues the command, the setpoint data typeis determined by the local data file type used to store it.

The PLC5 Typed Read commands for requesting data in integer or float format is exactlythe same messages. The UCM-DF1 driver cannot tell the requested data type from thecommand bytes received. Therefore, the returned data type has to be pre-configured in




UCM via the Ingersoll-Rand UCM-wizard tool. Default is the integer type. If a PLC5 orSLC5/04 issues the command, the local data file used to store the gathered data should bethe same type. Otherwise, you get erroneous data or an error status code due to data typemismatch.

CMC as SLC5/04As to treating CMC as a SLC5/04, the command initiator can issue a SLC Typed LogicalRead (Write) command to the CMC. Please see the section on Supported Functions fordetailed message format.

If the command initiator is another SLC5/04, you can do either integer or float data type.However, if the command initiator is a PLC5, only integer type is supported for the timebeing.

Data File Addressing for PLC5/SLC504When RSLogix software is used to program message instructions in PLC for sendingread/write commands to the CMC, the target data table address is in the form of eitherFxx:yyy or Nxx:yyy, where xx is the file number (10-14) and yyy (0-255) is the correspondingCMC data table address. The target file type (F for float, N for integer) should be consistentwith the local file type.

The UCM-DF1 interface designates file number 10 for discrete usage (read only). Eachelement represents 16 Boolean data bit-packed together in two bytes. File type can be eitherN (integer) or B (bit) type. The following table shows the address in file 10 for discretevalues.

PLCFile

CMC Data TableAddress

16 DiscretesPacked as Binary Bits in Two Bytes

Address (decimal) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0B10:10 160-175 175 174 173 172 171 170 169 168 167 166 165 164 163 162 161 160B10:11 176-191 191 190 189 188 187 186 185 184 183 182 181 180 179 178 177 176B10:12 192-207 207 206 205 204 203 202 201 200 199 198 197 196 195 194 193 192B10:13 208-223 223 222 221 220 219 218 217 216 215 214 213 212 211 210 209 208

Bit 10-15 of integer element 10 in data file 10 represents digital input channels 1-6 (CMCdata table address 170-175). Bit 0-9 of integer element 11 represent digital input channels 7-16 (CMC data table address 176-185). Bit 10-15 of integer element 11 represents digitaloutput channels 1-6 (CMC data table address 186-191). Bit 0-9 of integer element 12represent digital output channels 7-16 (CMC data table address 192-201). Bit 10-15 ofinteger element 11 represents digital output channels 1-6 (CMC data table address 186-191). Bit 10-15 of integer element 12 and bit 0-10 of integer element 13 represent variouscompressor states (CMC data table address 202-218).

Currently, CMC data table has 512 entries. In order to satisfy the (0-255) limit of elementsper data file for SLC5/04, the CMC data table is divided into two segments; each has 256entries. File number 11 is designated to the first 256 entries. File number 12 is for thesecond 256 entries. If the CMC data table gets expanded later, the subsequent file numberwill be used.

According to the above, N11:170 refers to the 170-th item in the CMC data table, which isthe digital input channel 1. Similarly, N12:170 will be the 426-th = (170+256) item in the CMCdata table. If an invalid file or element number is used, you will get a 3Fh-status error code.See the status error code section for details.



115

The number of bytes per element is 2 for integer type and 4 for float type. The assignedmessage length in elements for local data file should be a multiple of 2 for integer type. If it isan odd number, only the 2-byte integer (whole) part will be transmitted for the last data item.

Since the CMC has programmable analog and discrete inputs and outputs, the programmermust use the electrical schematic supplied with the contract to determine which functionname and units of measure are associated with each input and output.

CMC Data AddressingRefer to the table below for data addresses supported by the UCM-DF1 Interface.

DataAddress(decimal)

DataAddress

(hex)Description


DataAddress

(hex)Description

1 01 Analog Input, Ch 1 (J2-P1,3) 42 2A Analog Input, Ch 4 (J1-P4) – Hi Trip Setpoint2 02 Analog Input, Ch 2 (J2-P5,7) 43 2B Analog Input, Ch 4 (J1-P4) – Hi Alarm Setpoint3 03 Analog Input, Ch 3 (J1-P1) 44 2C Analog Input, Ch 4 (J1-P4) - Lo Alarm Setpoint4 04 Analog Input, Ch 4 (J1-P4) 45 2D Analog Input, Ch 4 (J1-P4) - Lo Trip Setpoint5 05 Analog Input, Ch 5 (J1-P5) 46 2E Analog Input, Ch 5 (J1-P5) - Hi Trip Setpoint6 06 Analog Input, Ch 6 (J1-P8) 47 2F Analog Input, Ch 5 (J1-P5) - Hi Alarm Setpoint7 07 Analog Input, Ch 7 (J1-P9) 48 30 Analog Input, Ch 5 (J1-P5) - Lo Alarm Setpoint8 08 Analog Input, Ch 8 (J1-P12) 49 31 Analog Input, Ch 5 (J1-P5) - Lo Trip Setpoint9 09 Analog Input, Ch 9 (J1-P13) 50 32 Analog Input, Ch 6 (J1-P8) - Hi Trip Setpoint

10 0A Analog Input, Ch 10 (J1-P16) 51 33 Analog Input, Ch 6 (J1-P8) - Hi Alarm Setpoint11 0B Analog Input, Ch 11 (J1-P17) 52 34 Analog Input, Ch 6 (J1-P8) - Lo Alarm Setpoint12 0C Analog Input, Ch 12 (J1-P20) 53 35 Analog Input, Ch 6 (J1-P8) - Lo Trip Setpoint13 0D Analog Input, Ch 13 (J1-P21) 54 36 Analog Input, Ch 7 (J1-P9) - Hi Trip Setpoint14 0E Analog Input, Ch 14 (J1-P24) 55 37 Analog Input, Ch 7 (J1-P9) - Hi Alarm Setpoint15 0F Analog Input, Ch 15 (J1-P25) 56 38 Analog Input, Ch 7 (J1-P9) - Lo Alarm Setpoint16 10 Analog Input, Ch 16 (J1-P28) 57 39 Analog Input, Ch 7 (J1-P9) - Lo Trip Setpoint17 11 Analog Input, Ch 17 (J1-P29) 58 3A Analog Input, Ch 8 (J1-P12) - Hi Trip Setpoint18 12 Analog Input, Ch 18 (J1-P32) 59 3B Analog Input, Ch 8 (J1-P12) - Hi Alarm Setpoint19 13 Analog Input, Ch 19 (J1-P33) 60 3C Analog Input, Ch 8 (J1-P12) - Lo Alarm Setpoint20 14 Analog Input, Ch 20 (J1-P36) 61 3D Analog Input, Ch 8 (J1-P12) - Lo Trip Setpoint21 15 Analog Input, Ch 21 (J1-P37) 62 3E Analog Input, Ch 9 (J1-P13) - Hi Trip Setpoint22 16 Analog Input, Ch 22 (J1-P40) 63 3F Analog Input, Ch 9 (J1-P13) - Hi Alarm Setpoint23 17 Analog Input, Ch 23 (J1-P41) 64 40 Analog Input, Ch 9 (J1-P13) - Lo Alarm Setpoint24 18 CT Input (J9-P1,2) 65 41 Analog Input, Ch 9 (J1-P13) - Lo Trip Setpoint25 19 Reserved 66 42 Analog Input, Ch 10 (J1-P16) - Hi Trip Setpoint26 1A Analog Output, Ch 1 (J3-P1,3) 67 43 Analog Input, Ch 10 (J1-P16) - Hi Alarm Setpoint27 1B Analog Output, Ch 2 (J3-P4,6) 68 44 Analog Input, Ch 10 (J1-P16) - Lo Alarm Setpoint28 1C Analog Output, Ch 3 (J3-P7,9) 69 45 Analog Input, Ch 10 (J1-P16) - Lo Trip Setpoint29 1D Analog Output, Ch 4 (J3-P10,12) 70 46 Analog Input, Ch 11 (J1-P17) - Hi Trip Setpoint30 1E Analog Input, Ch 1 (J2-P1,3) – Hi Trip Setpoint 71 47 Analog Input, Ch 11 (J1-P17) - Hi Alarm Setpoint31 1F Analog Input, Ch 1 (J2-P1,3) – Hi Alarm Setpoint 72 48 Analog Input, Ch 11 (J1-P17) - Lo Alarm Setpoint32 20 Analog Input, Ch 1 (J2-P1,3) – Lo Alarm Setpoint 73 49 Analog Input, Ch 11 (J1-P17) - Lo Trip Setpoint33 21 Analog Input, Ch 1 (J2-P1,3) – Lo Trip Setpoint 74 4A Analog Input, Ch 12 (J1-P20) - Hi Trip Setpoint34 22 Analog Input, Ch 2 (J2-P5,7) – Hi Trip Setpoint 75 4B Analog Input, Ch 12 (J1-P20) - Hi Alarm Setpoint35 23 Analog Input, Ch 2 (J2-P5,7) – Hi Alarm Setpoint 76 4C Analog Input, Ch 12 (J1-P20) - Lo Alarm Setpoint36 24 Analog Input, Ch 2 (J2-P5,7) – Lo Alarm Setpoint 77 4D Analog Input, Ch 12 (J1-P20) - Lo Trip Setpoint37 25 Analog Input, Ch 2 (J2-P5,7) – Lo Trip Setpoint 78 4E Analog Input, Ch 13 (J1-P21) - Hi Trip Setpoint38 26 Analog Input, Ch 3 (J1-P1) – Hi Trip Setpoint 79 4F Analog Input, Ch 13 (J1-P21) - Hi Alarm Setpoint39 27 Analog Input, Ch 3 (J1-P1) – Hi Alarm Setpoint 80 50 Analog Input, Ch 13 (J1-P21) - Lo Alarm Setpoint40 28 Analog Input, Ch 3 (J1-P1) – Lo Alarm Setpoint 81 51 Analog Input, Ch 13 (J1-P21) - Lo Trip Setpoint




41 29 Analog Input, Ch 3 (J1-P1) – Lo Trip Setpoint 82 52 Analog Input, Ch 14 (J1-P24) - Hi Trip Setpoint



117


DataAddress

(hex)Description


DataAddress

(hex)Description

83 53 Analog Input, Ch 14 (J1-P24) - Hi Alarm Setpoint 142 8E Start Timer84 54 Analog Input, Ch 14 (J1-P24) - Lo Alarm Setpoint 143 8F CT Ratio85 55 Analog Input, Ch 14 (J1-P24) - Lo Trip Setpoint 144 90 Reserved86 56 Analog Input, Ch 15 (J1-P25) - Hi Trip Setpoint 145 91 Reserved87 57 Analog Input, Ch 15 (J1-P25) - Hi Alarm Setpoint 146 92 Reserved88 58 Analog Input, Ch 15 (J1-P25) - Lo Alarm Setpoint 147 93 Reserved89 59 Analog Input, Ch 15 (J1-P25) - Lo Trip Setpoint 148 94 Power on hours90 5A Analog Input, Ch 16 (J1-P28) - Hi Trip Setpoint 149 95 Running Hours91 5B Analog Input, Ch 16 (J1-P28) - Hi Alarm Setpoint 150 96 Loaded Hours92 5C Analog Input, Ch 16 (J1-P28) - Lo Alarm Setpoint 151 97 Number of starts93 5D Analog Input, Ch 16 (J1-P28) - Lo Trip Setpoint 152 98 Reserved94 5E Analog Input, Ch 17 (J1-P29) - Hi Trip Setpoint 153 99 Reserved95 5F Analog Input, Ch 17 (J1-P29) - Hi Alarm Setpoint 154 9A Reserved96 60 Analog Input, Ch 17 (J1-P29) - Lo Alarm Setpoint 155 9B Reserved97 61 Analog Input, Ch 17 (J1-P29) - Lo Trip Setpoint 156 9C Reserved98 62 Analog Input, Ch 18 (J1-P32) - Hi Trip Setpoint 157 9D Reserved99 63 Analog Input, Ch 18 (J1-P32) - Hi Alarm Setpoint 158 9E Reserved100 64 Analog Input, Ch 18 (J1-P32) - Lo Alarm Setpoint 159 9F Reserved101 65 Analog Input, Ch 18 (J1-P32) - Lo Trip Setpoint 160 A0 Reserved102 66 Analog Input, Ch 19 (J1-P33) - Hi Trip Setpoint 161 A1 Reserved103 67 Analog Input, Ch 19 (J1-P33) - Hi Alarm Setpoint 162 A2 Inlet Valve Proportional Constant104 68 Analog Input, Ch 19 (J1-P33) - Lo Alarm Setpoint 163 A3 Inlet Valve Integral Constant105 69 Analog Input, Ch 19 (J1-P33) - Lo Trip Setpoint 164 A4 Reserved106 6A Analog Input, Ch 20 (J1-P36) - Hi Trip Setpoint 165 A5 Bypass Valve Proportional Constant107 6B Analog Input, Ch 20 (J1-P36) - Hi Alarm Setpoint 166 A6 Bypass Valve Integral Constant108 6C Analog Input, Ch 20 (J1-P36) - Lo Alarm Setpoint 167 A7 Reserved109 6D Analog Input, Ch 20 (J1-P36) - Lo Trip Setpoint 168 A8 Reserved110 6E Analog Input, Ch 21 (J1-P37) - Hi Trip Setpoint 169 A9 Compressor Control Mode111 6F Analog Input, Ch 21 (J1-P37) - Hi Alarm Setpoint 170 AA Digital Input, Ch 1 (J4-P2)112 70 Analog Input, Ch 21 (J1-P37) - Lo Alarm Setpoint 171 AB Digital Input, Ch 2 (J4-P3)113 71 Analog Input, Ch 21 (J1-P37) - Lo Trip Setpoint 172 AC Digital Input, Ch 3 (J4-P4)114 72 Analog Input, Ch 22 (J1-P40) - Hi Trip Setpoint 173 AD Digital Input, Ch 4 (J4-P5)115 73 Analog Input, Ch 22 (J1-P40) - Hi Alarm Setpoint 174 AE Digital Input, Ch 5 (J4-P6)116 74 Analog Input, Ch 22 (J1-P40) - Lo Alarm Setpoint 175 AF Digital Input, Ch 6 (J4-P7)117 75 Analog Input, Ch 22 (J1-P40) - Lo Trip Setpoint 176 B0 Digital Input, Ch 7 (J4-P8)118 76 Analog Input, Ch 23 (J1-P41) - Hi Trip Setpoint 177 B1 Digital Input, Ch 8 (J4-P9)119 77 Analog Input, Ch 23 (J1-P41) - Hi Alarm Setpoint 178 B2 Digital Input, Ch 9 (J5-P2)120 78 Analog Input, Ch 23 (J1-P41) - Lo Alarm Setpoint 179 B3 Digital Input, Ch 10 (J5-P3)121 79 Analog Input, Ch 23 (J1-P41) - Lo Trip Setpoint 180 B4 Digital Input, Ch 11 (J5-P4)122 7A Reserved 181 B5 Digital Input, Ch 12 (J5-P5)123 7B Reserved 182 B6 Digital Input, Ch 13 (J5-P6)124 7C Reserved 183 B7 Digital Input, Ch 14 (J5-P7)125 7D Reserved 184 B8 Digital Input, Ch 15 (J5-P8)126 7E Reserved 185 B9 Digital Input, Ch 16 (J5-P9)127 7F Reserved 186 BA Digital Output, Ch 1 (J15-P7,8)128 80 Reserved 187 BB Digital Output, Ch 2 (J15-P5,6)129 81 Reserved 188 BC Digital Output, Ch 3 (J15-P3,4)130 82 Reserved 189 BD Digital Output, Ch 4 (J15-P1,2)131 83 Surge Pressure Rate 190 BE Digital Output, Ch 5 (J14-P7,8)




132 84 Surge Current Rate 191 BF Digital Output, Ch 6 (J14-P5,6)133 85 Motor Current 192 C0 Digital Output, Ch 7 (J14-P3,4)134 86 User Pressure Setpoint 193 C1 Digital Output, Ch 8 (J14-P1,2)135 87 MinLoad (Throttle Limit, TL) 194 C2 Digital Output, Ch 9 (J13-P7,8)136 88 MaxLoad (High Load Limit, HLL) 195 C3 Digital Output, Ch 10 (J13-P5,6)137 89 Autodual Reload Percent 196 C4 Digital Output, Ch 11 (J13-P3,4)138 8A Autodual Unload Point 197 C5 Digital Output, Ch 12 (J13-P1,2)139 8B Autodual Unload Timer 198 C6 Digital Output, Ch 13 (J12-P7,8)140 8C Pressure Setpoint Ramp Rate 199 C7 Digital Output, Ch 14 (J12-P5,6)141 8D Inlet Valve Unload Position 200 C8 Digital Output, Ch 15 (J12-P3,4)



119


DataAddress

(hex)Description


DataAddress

(hex)Description

201 C9 Digital Output, Ch 16 (J12-P1,2) 213 D5 Compressor State - Loading202 CA Compressor State - Waiting 214 D6 Compressor State - Loaded203 CB Compressor State - Coasting 215 D7 Compressor State - Full Load204 CC Compressor State – Starting 216 D8 Compressor State - Analog Input Failed205 CD Compressor State - Not Ready 217 D9 Any Compressor Trip206 CE Compressor State - Ready 218 DA Any Compressor Alarm207 CF Compressor State - Surge Unload 220 DC Remote Acknowledge208 D0 Compressor State - Autodual Unload 221 DD Remote Reset209 D1 Compressor State - Unloading 222 DE Remote Load210 D2 Compressor State - Unloaded 223 DF Remote Unload211 D3 Compressor State - Min load 224 E0 Remote Start212 D4 Compressor State - Max load 225 E1 Remote Stop

Supported FunctionsThe listing below shows the DF1 commands supported by the CMC Microcontroller.

Command 0F/Function 68 - PLC5 Typed ReadThe CMC is treated as a PLC5 when this command is issued. This command reads a blockof data from CMC starting at a specified data table address.

As to the format of floating point number, Allen-Bradley DF1 protocol always put low bytefirst then high byte, low word first then high word, which is different from the UCM-MODBUSprotocol. The byte format for a floating point value, 105.4, is differentiated between the twointerfaces as below (Byte 1 to 4 is in the order of transmission):

Example: Reading an Analog InputAfter reviewing the Electrical Schematic for your compressor, you determine that the analoginput for system pressure is located on J1-P1 (Channel 3). From the CMC data table above,the address is 03h. The UCM should be configured to represent data type as desired.Following is a table illustrating how the PLC5 system address is mapped to the CMC datatable address.

CommandCode(hex)

FunctionCode(hex)

Function Name

0F 68 PLC5 Typed Read0F 67 PLC5 Typed Write0F A2 SLC Typed Logical Read0F AA SLC Typed Logical Write

Floating Point Byte RepresentationProtocol Byte 1 Byte 2 Byte 3 Byte 4

UCM-MODBUS 42 D2 CC CDUCM-DF1 CD CC D2 42




As 16-Bit Integer and FractionTo get the reading of system pressure as 16-bit integer and 16-bit fraction, the followingcommand is issued (data are presented in hexadecimal format):DLE STX DST SRC CMD STS TNS FN

CPacketOffset

TotalTrans

PLC5 System Address Size DLE ETX BCC

10 02 0D 11 0F 00 21 BD 68 00 00 02 00 07 00 0B 03 02 00 10 03 74

The response from this command is:DLE STX DST SRC CMD STS TNS A B DLE ETX BCC10 02 11 0D 4F 00 21 BD 99 09 05 42 64 00 5C 09 10 03 03

In the response above, the first two bytes (low byte first then high byte) in field B is theinteger portion of the system pressure (00-64h, 100 decimal). The second two bytes in fieldB are the fraction portion of the system pressure (09-5Ch, 2396 decimal). Each fraction hasa range between 0 and 9999. So the system pressure, expressed as a floating-pointnumber, is 100.2396 PSIG.

The following table contains a list of data types and the ID value of each supported by Allen-Bradley DF1 protocol:

Data Type ID Data Type1 bit2 bit string3 byte (or character) string4 integer5 Allen-Bradley timer6 Allen-Bradley counter7 Allen-Bradley general control structure8 IEEE floating point9 array of similar elements15 address data16 binary-coded decimal (BCD)

The first byte, 99h, in field A of the above response message is a flag byte, which has theformat below:

Data Type ID Data Type SizeBit: 7 6 5 4 3 2 1 0

1 0 0 1 1 0 0 1

If the data type ID is greater than 7, set bit 7 of this flag byte to 1 and insert the number ofbytes to follow that contains the data type ID value in bits 4, 5, and 6. These additional IDbytes follow directly after the flag byte. In the above response message, the additional onebyte is 09h, which means array of similar elements.

CMC PLC5 PLC5 System AddressData

AddressTarget Data

Table Address FileElementNumber

3 N11:3 07 00 0B 03254 N11:254 07 00 0B FE255 N11:255 07 00 0B FF FF 00256 N12:0 07 00 0C 00259 N12:3 07 00 0C 03



121

If the data type defined uses more than 7 bytes for each data element, enter 1 in bit 3 of theflag byte and enter the number of bytes to follow that contains the number of bytes used foreach data element. These additional size bytes follow the flag byte and any ID bytes.

The individual bytes in field A and B of the above response message is explained in thefollowing table:

Field Byte (hex) Definition99 flag byte09 data type ID byte: array of similar elements

A 05 number of bytes to follow42 descriptor byte

4: type ID for integer2: two bytes per element

64B 00 4 data bytes

5C09

As IEEE 32-Bit Floating Point NumberIf the UCM is configured to read data as floating point, the following command is sent:DLE STX DST SRC CMD STS TNS FN

CPacketOffset

TotalTrans


10 02 0D 11 0F 00 21 BD 68 00 00 01 00 07 00 0B 03 01 00 10 03

The response from this command is:DLE STX DST SRC CMD STS TNS A B DLE ETX BCC10 02 11 0D 4F 00 21 BD 99 09 06 94 08 C6 D4 DC 42 10 03

The individual bytes in field A and B of the above response message is explained in the tablebelow:

Field Byte (hex) means99 flag byte09 data type ID byte: array of similar elements

A 06 number of bytes to follow94 descriptor byte

9: one byte to follow4: four bytes per element

08 type ID for floating pointC6

B D4 4 data bytesDC42

After the proper byte swapping, the system pressure (42-DC-D4-C6), expressed as afloating point number is 110.4155731201 PSIG.

IEEE floating-point numbers are represented in 32 bits as shown below.




Convert hexadecimal words 1 and 2 (W1, W2) into decimal values ...

Determine the sign (positive = 0 or negative = 1) ...

Sign = (W2HB And 128) / 128, where And is defined as a bit-wise And

Sign = (66 And 128) / 128 = 0

Determine the exponent ...

Exponent = ((W2HB And 127) * 2) + INT (W2LB / 128), where INT is defined as INTEGER

Exponent = ((66 And 127) * 2) + INT (220/128) = 133

Determine the mantissa...

Mantissa = ((((W2LB And 127) * 256) + W1HB) * 256) + W1LB

Mantissa = ((((220 And 127) * 256) + 212) * 256) + 198 = 6083782

Putting the 32 bit IEEE value together...

Value = (-1sign) * (2(exponent - 127)) * ((Mantissa * 2-23) + 1)

Value = (-10) * (2(133- 127)) * ((6083782 * 2-23) + 1) = 110.4155731201

NOTE

When Sign = Exponent = Mantissa = 0, Value = 0. This is a special case for the aboveequation.

Example: Read Multiple Analog ChannelsThe procedure for reading multiple channels is the same as reading a single channel withthe exception of requesting more data. The message length in elements should be set asdesired but no more than 16 data at a time, because IRBUS can handle at most 16 data inone query for the time being.

NOTE

You must read a contiguous group of data (channels) for a single command.

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

exponent mantissa

sign

Word Byte Symbol Hex DecimalLo 1 Lo W1LB C6 198Lo 1 Hi W1HB D4 212Hi 2 Lo W2LB DC 220Hi 2 Hi W2HB 42 66



123

Example: Reading a Discrete ValueReading discrete values from file number 11 or higher is the same as reading analog data.To read a digital output (Channel 3, 188h) as a two-byte integer, the following command issent:DLE STX DST SRC CMD STS TNS FN

CPacketOffset

TotalTrans


10 02 0D 11 0F 00 A1 C2 68 00 00 01 00 07 00 0B BC 01 00 10 03 38

The response to this command is:DLE STX DST SRC CMD STS TNS A B DLE ETX BCC10 02 11 0D 4F 00 A1 C2 99 09 03 42 01 00 10 03 48

Example: Reading Multiple Discrete ValuesTo read digital output channels 1-6 as integers, the following command is sent:DLE STX DST SRC CMD STS TNS FN

CPacketOffset

TotalTrans


10 02 0D 11 0F 00 41 17 68 00 00 0C 00 07 00 0B BA 0C 00 10 03 2F

The response to this command is:DLE STX DST SRC CMD STS TNS A B10 02 11 0D 4F 00 41 17 99 09 19 42 00 00 00 00 00 00 00 00 01 00 00 00

B DLE ETX BCC00 00 00 00 00 00 00 00 00 00 00 00 10 03 3D

Example: Reading Bit-Packed Discrete DataReading discrete values from file number 10 is to read the 16 bit-packed discrete values in atwo-byte integer format. When the following command is sent,

DLE STX DST SRC CMD STS TNS FNC

PacketOffset

TotalTrans


10 02 0D 11 0F 00 61 C4 68 00 00 01 00 07 00 0A 0B 01 00 10 03 28

the response from this command is:DLE STX DST SRC CMD STS TNS A B DLE ETX BCC10 02 11 0D 4F 00 61 C4 99 09 03 42 28 10 10 10 03 4F

NOTE

The data value 10h in field B is transmitted as 10h 10h to be distinguished from thecontrol character DLE. Please see the DF1 Full-Duplex Protocol Message Framessection for more details.

In the above example, the local data file type can be either bit or integer types. Local dataelement B10:11 covers CMC data table address 176-191. Bit 10-15 is for digital outputchannels 1-6. You can determine the remote trouble contact (Channel 3, J15-P3,4) by bit 12in the returned integer. The table below graphically depicts the individual bit value for thereturned two-byte integer.




A bit response of 1 means that the output is ON and a response of 0 means that the outputis OFF.

Command 0F/Function 67 - PLC5 Typed Write

CAUTION


The CMC is treated as a PLC5 when this command is issued. This command writes data tothe CMC starting at the specified data table address. You can write to a setpoint with eitheran integer or floating point number.

Example: Presetting Analog Setpoints for 32-bit ValuesTo write 105.4 PSIG as a floating point number to the user pressure setpoint (CMC datatable address, 86h), issue the following command:


PacketOffset

TotalTrans

PLC5 System Address

10 02 0D 11 0F 00 81 CE 67 00 00 01 00 07 00 0B 86

A B DLE ETX BCC99 09 06 94 08 CD CC D2 42 10 03 93

The response from this command is:DLE STX DST SRC CMD STS TNS DLE ETX BCC10 02 11 0D 4F 00 81 CE 10 03 44

The difficulty in setting 32-bit values is determining the four data bytes for the number youwant to send. The process required is ...

1. Determine the sign (positive = 0 or negative = 1). This is the first bit.

2. Divide the decimal value by 2 until the result is less than 2, but greater than 1. Count thenumber of iterations required. Add 127 to the number of iterations. This result is theexponent. Convert this result to binary. These are the next eight bits.

Response (hex) Bit 7 6 5 4 3 2 1 0CMC DataAddress

183 182 181 180 179 178 177 176

Byte 1 28 0 0 1 0 1 0 0 0Bit 15 14 13 12 11 10 9 8

CMC DataAddress

191 190 189 188 187 186 185 184

Byte 2 10 0 0 0 1 0 0 0 0



125

3. From the result obtained from step 2, subtract 1. Then, multiply this result by 2. If theresult is less than 1, then the value of the first mantissa bit is 0. Otherwise, the mantissabit is 1. If the result is greater than or equal to 1, then subtract 1 from the result andproceed with step 3 until the result is 0 or you have gone through this process 23 times.

4. Combine all 32 bits from the steps above and convert this value to hexadecimal. These32 bits are the 4 hexadecimal data bytes needed for the command.

As an example, we will start with the decimal value of 105.4.

1. Since this is a positive number, the first bit is 0.

2. Determine the exponent bits by ...

It took us six iterations to get the result to a number that is less than two and greater than orequal to one. Now, we must add 127 for an exponent of 133. Converting this to binary, thenext eight bits are represented as 10000101.

3. Determine the mantissa bits by ...

From the table above, 10100101100110011001100 represent the next 23 bits.

Iteration Decimal Result1 105.40000 / 2 = 52.7000002 52.70000 / 2 = 26.3500003 26.35000 / 2 = 13.1750004 13.17500 / 2 = 6.5875005 6.58750 / 2 = 3.2937506 3.29375 / 2 = 1.646875

Iteration Decimal Operation Result Bit1 1.646875 - 1 * 2 = 1.29375 12 1.29375 - 1 * 2 = 0.5875 03 0.5875 * 2 = 1.175 14 1.175 - 1 * 2 = 0.35 05 0.35 * 2 = 0.7 06 0.7 * 2 = 1.4 17 1.4 - 1 * 2 = 0.8 08 0.8 * 2 = 1.6 19 1.6 - 1 * 2 = 1.2 1

10 1.2 - 1 * 2 = 0.4 011 0.4 * 2 = 0.8 012 0.8 * 2 = 1.6 113 1.6 - 1 * 2 = 1.2 114 1.2 - 1 * 2 = 0.4 015 0.4 * 2 = 0.8 016 0.8 * 2 = 1.6 117 1.6 - 1 * 2 = 1.2 118 1.2 - 1 * 2 = 0.4 019 0.4 * 2 = 0.8 020 0.8 * 2 = 1.6 121 1.6 - 1 * 2 = 1.2 122 1.2 - 1 * 2 = 0.4 023 0.4 * 2 = 0.8 0




4. Combining the bits in sign, exponent and then mantissa order ...

0100-0010-1101-0010-1100-1100-1100-1100

This converts to 42-D2-CC-CC in hexadecimal. To conform to DF1 floating point format, thebytes are swapped as CC-CC-D2-42.

Example: Presetting a 16-bit Integer and 16-bit Fraction Analog SetpointTo change the integer and fraction value for the user pressure setpoint to 105.4 PSIG, issuethe command below. The integer portion of the number 105 (00-69h) and the fraction 0.4 isconverted to 4000 (0F-A0h). These four bytes are placed in field B in the order of (69-00-A0-0F).


PacketOffset

TotalTrans

PLC5 System Address

10 02 0D 11 0F 00 41 D0 67 00 00 02 00 07 00 0B 86

A B DLE ETX BCC99 09 05 42 69 00 A0 0F 10 03 C0

The response from this command is:DLE STX DST SRC CMD STS TNS DLE ETX BCC10 02 11 0D 4F 00 41 D0 10 03 82

Example: Forcing a CoilForcing a single coil to either ON or OFF. Refer to the table below for each coil supported bythe UCM-DF1 interface. An integer value of one or greater forces the coil to be ON. Aninteger value of zero forces the coil to be OFF.

CMC Data TableAddress(decimal)

CMC Data TableAddress (hex)

Coil Name(Write only)

220 DC Remote Acknowledge221 DD Remote Reset222 DE Remote Load223 DF Remote Unload224 E0 Remote Start225 E1 Remote Stop

NOTE

For the CMC, forcing the above listed coils OFF is not meaningful because the defaultstate of each of the above coils is OFF. When using these commands, they should besent once (momentary) and the CMC will execute the commands.

NOTE



127





CAUTION

For all of the Remote Coils, the compressor’s REMOTE COMMUNICATIONSDISABLED/ENABLED selector switch must be in the ENABLED position for thesecommands to execute. When DISABLED, the CMC ignores these coils being forcedON.

To remotely acknowledge the compressor’s alarm or trip condition, the following commandis issued:


PacketOffset

TotalTrans

PLC5 System Address

10 02 0D 11 0F 00 E1 F8 67 00 00 01 00 07 00 0B DC

A B DLE ETX BCC99 09 03 42 01 00 10 03 BC

The response from this command is:DLE STX DST SRC CMD STS TNS DLE ETX BCC10 02 11 0D 4F 00 E1 F8 10 03 BA

The following command works the same:DLE STX DST SRC CMD STS TNS FN

CPacketOffset

TotalTrans

PLC5 System Address

10 02 0D 11 0F 00 41 E3 67 00 00 02 00 07 00 0B DC

A B DLE ETX BCC99 09 05 42 01 00 00 00 10 03 6E

The response from this command is:DLE STX DST SRC CMD STS TNS DLE ETX BCC10 02 11 0D 4F 00 41 E3 10 03 6F

Example: Forcing Multiple CoilsForces each coil in a series of contiguous coils to either ON or OFF. Refer to the data tableabove for a coil list supported by the UCM-DF1 Interface.

NOTE


To force a reset (CMC data table address, DDh) and start (CMC data table address, E0h) ofthe compressor the following command is sent:



129


PacketOffset

TotalTrans

PLC5 System Address

10 02 0D 11 0F 00 21 0C 67 00 00 08 00 07 00 0B DD

A B DLE ETX BCC99 09 11 42 01 00 00 00 01 00 00 00 01 00 00 00 01 00 00 00 10 03 4F

The response from this command is:DLE STX DST SRC CMD STS TNS DLE ETX BCC10 02 11 0D 4F 00 21 0C 10 03 66

The number of contiguous coils is four (DD, DE, DF, and E0h). The message length ofinteger elements is 8 and the number of data bytes in field B is 16.

Command 0F/Function A2 - SLC Typed Logical ReadThe CMC is treated as an SLC5/04 when this command is issued. This function reads ablock of data from CMC starting at a specified data table address.

Example: Reading an Analog ValueTo read the pressure setpoint (CMC data table address 86h) as a floating point number, thefollowing command is issued:

DLE STX DST SRC CMD STS TNS FNC ByteSize

FileNo.

FileType

EleNo.

S/EleNo.

DLE ETX BCC

10 02 0D 0B 0F 00 D4 19 A2 04 0B 8A 86 00 10 03 2B

The response from this command is:DLE STX DST SRC CMD STS TNS Data DLE ETX BCC10 02 0B 0D 4F 00 D4 19 CD CC D2 42 10 03 FF

The important command bytes are explained below:

Field DescriptionByte Size The number of data bytes to be read.

File Number Address files 0-255 only. For CMC, file 10 is designated for discreteonly. File (11+N) is for the (N+1) th 256 entries in the CMC data table.

File Type 85h: bit89h: integer8Ah: float

Element Number Address elements 0-255 only. The address byte format is the sameas PLC5 for CMC.

254: (FE)255: (FF-FF-00)

Sub-Element Number Not used, always 00h.

The four bytes in data field of the response message is converted to a floating point number,105.4 PSIG.

To read the pressure setpoint value as integer, the following command is sent:DLE STX DST SRC CMD STS TNS FNC Byte

SizeFileNo.

FileType

EleNo.

S/EleNo.

DLE ETX BCC

10 02 0D 0B 0F 00 D4 27 A2 04 0B 89 86 00 10 03 1E




The response from this command is:DLE STX DST SRC CMD STS TNS Data DLE ETX BCC10 02 0B 0D 4F 00 D4 27 69 00 A0 0F 10 03 86

The first two bytes in data field represent the integer portion, 106 (00-69h), of the setpoint.The second two bytes represent the fraction portion, 4000 (0F-A0h), of the setpoint.

Example: Reading Multiple Analog ValuesThe following command reads analog inputs channels 3-9 as integer:


FileNo.

FileType

EleNo.

S/EleNo.

DLE ETX BCC

10 02 0D 0B 0F 00 D5 A9 A2 1C 0B 89 03 00 10 03 06

The response from this command is:DLE STX DST SRC CMD STS TNS Data10 02 0B 0D 4F 00 D5 A9 63 00 5C 21 09 00 0F 0A 20 00 D6 00 62 00 E7 0B

Data DLE ETX BCC00 00 FF 0B 2E 00 66 14 BC 00 83 1E 10 03 C0

Example: Reading Single Discrete DataAfter reviewing the Electrical Schematic for your compressor, you determine that the digitalinput for emergency stop push button is located on J4-P5 (Channel 4). The CMC data tableaddress is ADh for the input in question. Therefore, to read the state of the emergency stoppush button as a two byte integer, the following command is issued:


FileNo.

FileType

EleNo.

S/EleNo.

DLE ETX BCC

10 02 0D 0B 0F 00 D6 79 A2 02 0B 89 AD 00 10 03 A5

The response from this command is:DLE STX DST SRC CMD STS TNS Data DLE ETX BCC10 02 0B 0D 4F 00 D6 79 01 00 10 03 49

The data response (01) means that the input is ON, or the emergency stop push button ispressed.

Example: Reading 16 Bit-Packed Discrete DataTo read 16 bit-packed discrete values for digital outputs as a two-byte integer, the followingcommand is sent:


FileNo.

FileType

EleNo.

S/EleNo.

DLE ETX BCC

10 02 0D 0B 0F 00 E1 41 A2 02 0A 85 0B 00 10 03 79

Note that the file number must be 10. The local data file used to store the returned data canbe either bit (85h) or integer (89h) type. The response from this command is:

DLE STX DST SRC CMD STS TNS Data DLE ETX BCC



131

10 02 0B 0D 4F 00 E1 41 28 10 10 10 03 3F

Please refer to the PLC5 Typed Read command section for the method to interpret the 16-bit discrete values.

Command 0F/Function AA - SLC Typed Logical WriteThe CMC is treated as a SLC5/04 when this command is issued. This command writes ablock of data to CMC starting at a specified data table address. You can write to a setpointwith either an integer or floating point number.

Example: Presetting Analog Setpoint for 32-bit ValueTo write 105.4 PSIG as a floating point number to the user pressure setpoint (CMC datatable address, 86h), issue the following command:


FileNo.

FileType

EleNo.

S/EleNo.

Data DLE ETX BCC

10 02 0D 0B 0F 00 E1 70 AA 04 0B 8A 86 00 CD CC D2 42 10 03 12

The response from this command is:DLE STX DST SRC CMD STS TNS DLE ETX BCC10 02 0B 0D 4F 00 E1 70 10 03 48

Example: Presetting a 16-bit Integer and 16-bit Fraction Analog SetpointTo change the integer and fraction value for the user pressure setpoint to 105.4 PSIG, issuethe command below. The integer portion of the number 105 (00-69h) and the fraction 0.4 isconverted to 4000 (0F-A0h). These four bytes are placed in field B in the order of (69-00-A0-0Fh).


FileNo.

FileType

EleNo.

S/EleNo.

Data DLE ETX BCC

10 02 0D 0B 0F 00 E1 82 AA 04 0B 89 86 00 69 00 A0 0F 10 03 96

The response from this command is:DLE STX DST SRC CMD STS TNS DLE ETX BCC10 02 0B 0D 4F 00 E1 82 10 03 36

Example: Forcing a CoilForces a single coil to either ON or OFF. Refer to the CMC data table for each coilsupported by the UCM-DF1 interface. See the same example in the PLC5 Typed Writecommand section for more details.

To remotely acknowledge the compressor’s alarm or trip condition, the following commandis issued:


FileNo.

FileType

EleNo.

S/EleNo.

Data DLE ETX BCC

10 02 0D 0B 0F 00 E1 A3 AA 04 0B 89 DC 00 01 00 00 00 10 03 36

The response from this command is:DLE STX DST SRC CMD STS TNS DLE ETX BCC




10 02 0B 0D 4F 00 E1 A3 10 03 15

To remotely acknowledge the compressor’s alarm or trip condition, the following commandworks the same:


FileNo.

FileType

EleNo.

S/EleNo.

Data DLE ETX BCC

10 02 0D 0B 0F 00 E1 AD AA 02 0B 89 DC 00 01 00 10 03 2E

The response from this command is:DLE STX DST SRC CMD STS TNS DLE ETX BCC10 02 0B 0D 4F 00 E1 AD 10 03 0B

Example: Forcing Multiple CoilsForces each coil in a series of contiguous coils to either ON or OFF. Refer to the CMC datatable for a list of coils supported by the UCM-DF1 interface. To force a reset (CMC datatable address, DDh) and start (E0h) of the compressor, the following command is sent:


FileNo.

FileType

EleNo.

S/EleNo.

Data

10 02 0D 0B 0F 00 E2 3A AA 10 10 0B 89 DD 00 01 00 00 00 01 00 00 00

Data DLE ETX BCC01 00 00 00 01 00 00 00 10 03 8E

NOTE

The byte size value 10h is transmitted as 10h 10h to be distinguished from the controlcharacter DLE.

The response from this command is:DLE STX DST SRC CMD STS TNS DLE ETX BCC10 02 0B 0D 4F 00 E2 3A 10 03 7D

The number of contiguous coils is four (DD, DE, DF, and E0h). The assigned localmessage buffer length is 8 integer elements, which is 16-byte long.

Allen-Bradley SLC 504 Example

Data Files

RSLogix 500 Ladder DiagramThe following ladder logic example is the fastest and most reliable method for gathering datafrom a CMC.



133

UCM STS Error CodesSTS Code

(hex) Definition00 Success - no error10 Illegal command or function30 Remote node host is missing, disconnected, or shutdown3F Illegal CMC data address or countD0 Illegal data typeE0 Cannot form CMC data table query/set list

NOTE

The UCM-DF1 driver does not support EXT STS. According to Allen-Bradley DF1protocol convention, EXT STS is part of the message only if STS = F0h.

N7:0U15

U15

N7:0First Pass

S2:1

150000

EN

DN

ER

MSGRead/Write MessageTypeRead/WriteTarget DeviceLocal/RemoteControl BlockControl Block Length

Setup Screen

Peer-To-PeerRead

500CPULocalN7:0

14

0001

N7:0

120002

N7:0

10

EN

DN

ER

MSGRead/Write MessageTypeRead/WriteTarget DeviceLocal/RemoteControl BlockControl Block Length

Setup Screen

Peer-To-PeerRead

500CPULocalN7:20

14

0003N7:0

13

N7:20U15

N7:20

120004

N7:20

10

N7:0U15

N7:20

130005

N7:20

10

N7:0

13

END0006




When the CMC receives a DF1 command without any communication error and thecommand is executed successfully, a normal response with status code 00h is returned.

If the UCM dose not receive the command due to a communication error, no response isreturned and the command initiator will eventually time out.

If the UCM dose receive the command, but detects error (invalid BCC/CRC...), controlcharacters DLE NAK is returned to the command initiator, which in turns retransmits thecommand message and restarts a time out to wait for the response. This can be repeated afew times depending on the limit preset for retransmission. Once the limit is exceeded, thecommand initiator is informed of the failure and proceeds to the next command.

If the time out expired before a response is received, the command initiator sends out DLEENQ control characters to request a retransmission of the last response. It restarts a timeout and wait for the response. There is a limit on the number of inquiries allowed percommand message. When this limit is exceeded, the command initiator proceeds to thenext command.

When UCM receives DLE ENQ or DLE NAK message, it resends the last response to thecommand initiator. When DLE ACK message is received by the UCM, no response isreturned.

When the UCM receives a command without any communication error, but cannot handle it,the UCM will return an exception response with the appropriate status code informing thecommand initiator of the nature of failure.

NOTE

The table below explains the meanings of different control symbols for DF1 protocol:

Control Symbol DefinitionDLE ACK a message frame has been successfully receivedDLE NAK a message frame was not received successfullyDLE ENQ request retransmission of a response from the destination node

Communication ParametersConfiguration of the UCM RS-422 port’s communication speed (baud rate), parity, numberof data bits, number of stop bits... is available through the Ingersoll-Rand UCM-Wizard Tooland will be configured by a certified Ingersoll-Rand Service Representative. The settingsshould be the same as the 1770-KF2 interface module.

Network SetupThe network diagram that follows depicts the communication interface between Allen-Bradley DF1 network and Ingersoll-Rand CMC Microcontroller.

The 1770-KF2 always acts as a slave. The slave cannot initiate a command; i.e., the UCMcannot initiate a command over DH+ network. It only returns response messages to queriesthat are addressed to them individually. Broadcast is not supported over the DF1 network.



135

UniversalCommunicationModule (UCM)

IRBUS (RS-485) Networkfor Base Control Modulesand UniversalCommunication Modules,Twisted Pair Wires withGround (3 Wires)

Allen-Bradley1770-KF2

Interface Module

INGERSOLL-RANDService Tool

RS-232 toRS-422/RS-485

Converter

UniversalComm.Module(UCM)


IRBUSAddress: 2

BaseControlModule(BCM)

IRBUSAddress: 1

RS-232Cable


CMC Panel

Serial Port(COM1)

Service ToolPlug onPanel Door

RS-232Cable

Serial Port(COM1)

Modbus Network #1Full or Half DuplexRS-422 or RS-485

INGERSOLL-RANDCEM for Windows

DF1 NetworkFull Duplex RS-422A

IRBUSAddress: 6

IRBUSAddress: 5

IRBUSAddress: 4


Next CMC Panel(s) foruse in CEM for Windows

To DH+Network




1770-KF2 SetupA 1770-KF2 module links asynchronous devices (RS-422A or RS-232C) to an Allen-BradleyData Highway or Data Highway Plus network. The 1770-KF2 module has 8 switchassemblies that let you select various communication options. The switch assemblies areshown in the diagram below:

Switch Assembly Communication OptionSW-1 Asynchronous link features

SW-2, SW-3, SW-4 Node numberSW-5 Network link communication rateSW-6 Asynchronous link communication rateSW-7 DH/DH+ network link sectionSW-8 RS-232C/RS-422A selection

CAUTION

The 1770-KF2 module reads the status of these communication optionswitches only at power up, so you need to change switch settings with 1770-KF2powered off.

SW-1 (Asynchronous Link Features)The following table shows the different combinations available for setting the asynchronouslink with the 5 dipswitches of SW-1.

SW-1 Settings

ProtocolErrorCheck Parity

EmbeddedResponse 1 2

3(DuplicateMessage)ON: ignoreOFF: accept

4(Hand

Shake)5

Full Duplex BCC None No OFF OFF OFF OFF OFFFull Duplex BCC Even No ON OFF OFF OFF OFFFull Duplex BCC None Yes OFF ON OFF OFF OFFFull Duplex BCC Even Yes ON ON OFF OFF OFFFull Duplex CRC None Yes OFF ON OFF OFF ON

CAUTION

Only the UCM-DF1 driver supports the full duplex options. Half duplex is notsupported.



137

SW-2, SW-3, SW-4 (Node Address)These three switch assemblies are used to set the network node number of the 1770-KF2module. Set both switches in SW-2 OFF for DH+ link because the node number should bea 2-digit octal number that identifies the 1770-KF2 as a unique node on DH+. Valid nodenumbers for 1770-KF2 in DH+ network are 00 to 77 octal.

First digit (SW-2) should always be set to zero.

SW-2 Setting1 2 Digit

OFF OFF 0OFF ON 1ON OFF 2ON ON 3

Second and third digits:

SW-3, SW-4 Setting1 2 3 Digit

OFF OFF OFF 0OFF OFF ON 1OFF ON OFF 2OFF ON ON 3ON OFF OFF 4ON OFF ON 5ON ON OFF 6ON ON ON 7

SW-5 (Network Link Communication Rate)Switch assembly SW-5 lets you select the communication rate for the 1770-KF2 module’snetwork link (DH+). Set both switches ON for a network communication rate of 57,600 bitsper second. Be sure to set all modules on the same DH+ network for this communicationrate.

SW-6 (Asynchronous Link Communication Rate and Diagnostic Commands)Switches #1, #2, #3 of SW-6 let you select the communication rate for the 1770-KF2module’s asynchronous port. Meanwhile, switch #4 determines how 1770-KF2 moduletreats diagnostic commands sent by a remote DH+ node. It is recommended to set at 9600baud or higher, and execute received diagnostic commands.

SW-6 Setting4

Execute received diagnostic commands ONPass any received diagnostic commands to the attached asynchronous

deviceOFF

The available baud rate settings are shown below:

Baud Rate SW-6 Setting(Bits per second) 1 2 3

110 OFF OFF OFF300 ON OFF OFF600 OFF ON OFF




1200 ON ON OFF2400 OFF OFF ON4800 ON OFF ON9600 OFF ON ON19200 ON ON ON

SW-7 (Network Link Selection)UCM only supports DH+ network. SW-7 should always select DH+.

Network SW-7 SettingMode 1 2

DH OFF OFFDH+ ON OFF

SW-8 (RS-232C/RS-422A Selection)The UCM-DF1 interface uses RS-422 communication. SW-8 should select RS422.

Communication

SW-8 Setting

Type 1 2RS-232C OFF ONRS-422A ON OFF

Wiring Diagram for RS-422A

UCMRS-422

1770 KF2ModuleRS-422

1

RX+

RX-

TX+

TX-

14

25

16

18

4

5

6

8

20

TX+

TX-

RX-

RX+

GND

Cable not to exceed 4000 feet



139




DocumentationAn Electrical Schematic drawing is provided as standard after order placement. Control PanelOutline drawings are optional. Logic diagrams are considered proprietary and are not available.

System Information

Status CodesThe following table lists the status codes for the Base Control Module (BCM) only. Thesecodes indicate every operating condition, both normal and abnormal, for the system. A codealways exists for the system; for example, Status 05h indicates that the system is runningproperly.

These codes, except Status 00h and 05h, are shown on a blank screen in the upper lefthand corner of the Operator User Interface (OUI). Since Status 00h and 05h are normaloperating conditions, these codes are not displayed. When a code is displayed, contact yourlocal Ingersoll-Rand Service Representative.

StatusCode Definition Comments00h Booting The BCM is in the boot process. This is a normal process during BCM power up.

This state will not be displayed.01h Stay In Boot The BCM is held in boot mode by the hardware configuration. This condition exists

only when the boot jumper (hardware device) is plugged into the display (OUI)port. This hardware jumper is only required when doing system levelreprogramming of the module.

02h ROM CRC Failed The BCM software is not valid. This condition occurs when the CRC (CyclicRedundancy Check) calculated by the module does not equal the CRC valuewritten to the module when programmed. This would typically occur when theprogramming process is aborted (halted). The module must be reprogrammed.

03h Commanded To Boot The BCM is currently in the process of being programmed. If this message doesnot disappear after programming is completed, power cycle the unit.

04h Invalid Application The BCM software has failed to operate properly. Cycling the power on the modulewill restart the system. Once restarted, the program will operate properly until thesame condition reoccurs.

05h Application Running Normal operating condition. This state will not be displayed.06h Fatal Exit Operating system error. Cycling the power on the module will restart the system.

Once restarted, the program will operate properly until the same conditionreoccurs.

07h System Error Operating system error. Cycling the power on the module will restart the system.Once restarted, the program will operate properly until the same conditionreoccurs.

08h Incompatible SoftwareVersions

The BCM application software and tables are not compatible. The module must bereprogrammed.

09h A-D System Error Analog input system error. A hardware malfunction has occurred.0Ah D-A System Error Analog output system error. A hardware malfunction has occurred.0Bh Digital I/O System Error Digital input and output system error. A hardware malfunction has occurred.0Ch Logic Engine System or

Loop Task ErrorLadder logic processing system or loop task error. The module must bereprogrammed.

0Dh Comparator System Error Comparator system error. The module must be reprogrammed.0Eh Operator User Interface

ErrorOperator User Interface system error. Cycling the power on the module will restartthe system. Once restarted, the program will operate properly until the samecondition reoccurs.

0Fh Data Logging System Error Data logging system error. Cycling the power on the module will restart thesystem. Once restarted, the program will operate properly until the same condition



141

reoccurs.10h Low Power Power supply voltage (+24 VDC) dropped below minimum operating level. Check

power supply. Cycle power when voltage is within proper operating limits. Oncerestarted, the program will operate properly until the same condition reoccurs.




StatusCode Definition Comments11h Task Overrun System processing capabilities do not meet requirements for operation. Cycling the

power on the module will restart the system. Once restarted, the program willoperate properly until the same condition reoccurs.

12h Watchdog Failure The internal backup system monitor is not operational. BCM hardware should bereplaced. Cycling the power on the module will restart the system. Once restarted,the program will operate properly until the same condition reoccurs.

13h Intermodule Data Error An error has occurred while generating a message to be sent from one BCM to theother BCM in a multi-module configuration. The module must be reprogrammed.

14h Calculation Block Error A stack underflow or overflow has occurred in a calculation block. The modulemust be reprogrammed.

15h Interpolation System Error An error has occurred in the interpolation block. The module must bereprogrammed.

16h Calibration System Error Occurs during initialization of the EEPROM block. The module must bereprogrammed.



143

Base Control Module (BCM)Module Layout

J3-Analog Outputs(4-20mA)

Channels 1-4

Pin 7

Pin 1


Pin 1

Pin 5


Pin 1

Pin 25

Pin 1

Pin 1

Pin 1

Pin 1


Channels 1-8


Channels 9-16

J6-RS232 SerialData Link (Display),

Female DB9

J7-RS485 SerialData Link (IRBUS)

Pin 1

J8-Speed SensorInput (1-150 Hz)

J9-Current TransformerInput (0-5 Amps)

J12-Digital Outputs, Channels 16-13

J10-Power Input(24 VDC)

J13-Digital Outputs, Channels 12-9J14-Digital Outputs, Channels 8-5

J15-Digital Outputs, Channels 4-1

F102-Fuse for AnalogI/O(J1, J2 and J3)

F101-Fuse for OperatorUser Interface (Display)

F100-Fuse for BaseModule CPU Card

Tadiran TL-5101,3.6V 1/2 AA Battery

All Fuses are 5x20mm, GMA1.5 amp, Fast Blow

F103-Fuse for DigitalInputs (J4 and J5)

Pin 1 Pin 1 Pin 1 Pin 1




Connector Description

Tag Type Channel Module Connector Mating Connector

J1 Grounded Analog Inputs, 4-20 mA 3-23 (12) Phoenix MDSTB2, 5/2-G-5, 08

(2) Phoenix MDST2, 5/24-3T-5, 08

J2 Floating Analog Inputs, 4-20 mA 1-2 (2) Phoenix MDSTB2, 5/2-G-5, 08

(2) Phoenix MDST2, 5/4-3T-5, 08

J3 Analog Outputs, 4-20 mA 1-4 (3) Phoenix MDSTB2, 5/2-G-5, 08

(2) Phoenix MDST2, 5/6-3T-5, 08

J4J5

Digital (Discrete) Inputs, 24 VDC 1-89-16

Phoenix MSTBA 2,5/10-G-5, 08

Phoenix MSTB 2,5/10-ST-5, 08

J6 RS232 Serial Data Link (OperatorUser Interface)

na 9 Position “D” SubMiniature (Female)

9 Position “D” SubMiniature (Male)

J7 RS485 (IRBUS) Serial Data Link na Phoenix MSTBA 2,5/6-G-5, 08


J8 Speed Sensor Input, VariableReluctance

Phoenix MSTBA 2,5/3-G-5, 08


J9 Current Transformer Input na Terminal Strip Wire LugsJ10 Power na Phoenix MSTBA2,

5/5-G-5, 08Phoenix MSTB 2,

5/5-ST-5, 08J12J13J14J15

Digital Outputs 13-169-125-81-4

(4) Phoenix MSTBA2, 5/8-G-5, 08

(4) Phoenix MSTB2, 5/8-ST-5, 08

NOTES:

1. BCM Weight: 1775 ± 177g [3.92 ± .39 lb.]

2. BCM Size: Length=355.6 mm [14.0 in] x Width=247 mm [9.7 in] x Depth=45 mm [1.8 in]

3. To ensure chassis ground, install 12-gauge ground strap between this module and theNEMA enclosure. Place external tooth lock washer between this module and the groundstrap.

4. “na” is defined as “not applicable”.

5. All Phoenix connectors may be replaced with an equal supplier.



145

Connector Input and Output (I/O)Pin J1-Grounded Analog Inputs Pin J3-Analog Outputs Pin J8-Speed Sensor1 Analog Input Channel 3 1 Analog Output Channel 1+ 1 SS+2 Power 24 VDC, Channels 3 & 4 2 Power 24 VDC, Channels 1 & 2 2 SS-3 Shield, Channels 3 & 4 3 Analog Output Channel 1- 3 SS Ground

4 Analog Input Channel 4 4 Analog Output Channel 2+

5 Analog Input Channel 5 5 Shields, Channels 1 & 2 Pin J9-Current Transformer6 Power 24 VDC, Channels 5 & 6 6 Analog Output Channel 2- 1 CT+7 Shield, Channels 5 & 6 7 Analog Output Channel 3+ 2 CT-

8 Analog Input Channel 6 8 Power 24 VDC, Channels 3 & 4

9 Analog Input Channel 7 9 Analog Output Channel 3- Pin J10-Power10 Power 24 VDC, Channels 7 & 8 10 Analog Output Channel 4+ 1 Power +24V DC11 Shield, Channels 7 & 8 11 Shields, Channels 3 & 4 2 Power Ground12 Analog Input Channel 8 12 Analog Output Channel 4- 3 Chassis Ground

13 Analog Input Channel 9 4 Display Power +24VDC

14 Power 24 VDC, Channels 9 & 10 Pin J4-Digital Inputs 5 Display Power Ground

15 Shield, Channels 9 & 10 1 Power 24 VDC, Channels 1-8

16 Analog Input Channel 10 2 Digital Input Channel 1 Pin J12-Digital Outputs17 Analog Input Channel 11 3 Digital Input Channel 2 1 Digital Output Channel 1618 Power 24 VDC, Channels 11 & 12 4 Digital Input Channel 3 2 Digital Output Channel 1619 Shield, Channels 11 & 12 5 Digital Input Channel 4 3 Digital Output Channel 1520 Analog Input Channel 12 6 Digital Input Channel 5 4 Digital Output Channel 1521 Analog Input Channel 13 7 Digital Input Channel 6 5 Digital Output Channel 1422 Power 24 VDC, Channels 13 & 14 8 Digital Input Channel 7 6 Digital Output Channel 1423 Shield, Channels 13 & 14 9 Digital Input Channel 8 7 Digital Output Channel 1324 Analog Input Channel 14 10 Ground, Channels 1-8 8 Digital Output Channel 13

25 Analog Input Channel 15

26 Power 24 VDC, Channels 15 & 16 Pin J5-Digital Inputs Pin J13-Digital Outputs27 Shield, Channels 15 & 16 1 Power 24 VDC, Channels 9-16 1 Digital Output Channel 1228 Analog Input Channel 16 2 Digital Input Channel 9 2 Digital Output Channel 1229 Analog Input Channel 17 3 Digital Input Channel 10 3 Digital Output Channel 1130 Power 24 VDC, Channels 17 & 18 4 Digital Input Channel 11 4 Digital Output Channel 1131 Shield, Channels 17 & 18 5 Digital Input Channel 12 5 Digital Output Channel 1032 Analog Input Channel 18 6 Digital Input Channel 13 6 Digital Output Channel 1033 Analog Input Channel 19 7 Digital Input Channel 14 7 Digital Output Channel 934 Power 24 VDC, Channels 19 & 20 8 Digital Input Channel 15 8 Digital Output Channel 9

35 Shield, Channels 19 & 20 9 Digital Input Channel 16

36 Analog Input Channel 20 10 Ground, Channels 9-16 Pin J14-Digital Outputs

37 Analog Input Channel 21 1 Digital Output Channel 8

38 Power 24 VDC, Channels 21 & 22 Pin J6-RS232 (Display) 2 Digital Output Channel 839 Shield, Channels 21 & 22 1 Not Used 3 Digital Output Channel 740 Analog Input Channel 22 2 Receive Data (RxD) 4 Digital Output Channel 741 Analog Input Channel 23 3 Transmit Data (TxD) 5 Digital Output Channel 642 Power 24 VDC, Channel 23 4 Not Used 6 Digital Output Channel 643 Shield, Channel 23 5 Signal Ground 7 Digital Output Channel 544 Spare 6 Not Used 8 Digital Output Channel 5

45 Spare 7 Not Used

46 Power 24 VDC, Spare 8 Not Used Pin J15-Digital Outputs47 Shield, Spare 9 Not Used 1 Digital Output Channel 4

48 Spare 2 Digital Output Channel 4

Pin J7-RS485 (IRBUS) 3 Digital Output Channel 3

Pin J2-Floating Analog Inputs 1 Data Link 1+ 4 Digital Output Channel 31 Analog Input Channel 1+ 2 Data Link 1- 5 Digital Output Channel 22 Power 24 VDC, Channel 1 3 Data Link Ground 6 Digital Output Channel 23 Analog Input Channel 1- 4 Data Link 1+ 7 Digital Output Channel 14 Shield, Channel 1 5 Data Link 1- 8 Digital Output Channel 1

5 Analog Input Channel 2+ 6 Data Link Ground

6 Power 24 VDC, Channel 27 Analog Input Channel 2-8 Shield, Channel 2




Operator User Interface Module (OUI)Module Layout

Connector DescriptionTag Type Module Connector Mating Connector

J1 RS232 Port 9 Position “D” SubMiniature (Female)


J2 Input Power Phoenix MSTBA2,5/2-G-5, 08

Phoenix MSTW2,5/2-ST-5, 08

NOTES:

1. OUI Weight: 410 g [0.90 lb.]

2. OUI Size: Length=267 mm [10.5 in] x Width=175 mm [6.9 in] x Depth=60 mm [2.4 in]


Connector Input and Output (I/O)Pin J1-RS232 Port Pin J2-Input Power1 No Connection 1 +12 To +24 VDC (VPOWER)2 Transmit (TX) 2 Ground (GND)3 Receive (RX)4 No Connection5 Signal Common6 No Connection7 No Connection8 No Connection9 No Connection

J1-RS232 Port

Pin 1

J2-Input Power

Pin 1

Side View



147

CMC User Interface/Bezel Cleaning InstructionsThe following procedure is recommended to clean the CMC User Interface vinyl overlaymaterial and/or the User Interface bezel.

1. Stop the compressor and depress the maintained ‘Emergency Stop’ push-button, thiswill prevent an inadvertent start up or trip of the compressor during the cleaning process.

2. Dampen a soft cloth or paper towel with water and wipe any dust, dirt or liquids from thesurface of the User Interface, do not use an abrasive pad or brush to clean the surfaceof the User Interface vinyl overlay or bezel.

3. If more aggressive measures are required to clean the User Interface and/or bezelsurface use a mild non-abrasive household cleaner (such as Formula 409, Fantastik,etc.) sprayed or wiped directly onto the surface to be cleaned. Dampen a soft cloth orpaper towel with water and wipe any remaining cleaner from the surfaces.

Ingersoll-Rand Company recommends the following for cleaning the OUI and bezel:

Cleaners: Water or mild house hold cleaner, no petroleum or acetone based fluids.

Cleaning wipes: Soft cotton clothe or paper towels.

Backlight Replacement ProcedureTools Needed:

1. Flat blade screwdriver with a small tip (1/8 inch)2. Number 1 Phillips Screwdriver3. Electrostatic Discharge Strap Connected to Earth Ground




Step 1 Step 2

J2 DisplayPower

J1 UserTerminal

+-

Removecabling

Loosen screws, slide right

Lift cover to removeUnplug connectorand remove nylon

cable retainer screws

Step 3 Step 4

Remove screws f rom thelower printed circuitboard, then use a

screwdriver to gently prythe backlight panel loose.

Use circular stand-offs torest screwdriver shaftagainst while pryingbacklight panel out.

The backlight is part of a larger panelthat is removed as an assembly.



149

Step 5 Step 6

Slide the backlight panelin place and align the

screw holes so the screwsmay be inserted and

tightened.

Backlight panel isinserted into displaybetween the circuit boardand the LCD glass withthe white plastic backingsheet and wires facingtoward the circuit boards.

Insert screws being carefulnot to over tighten.

Route wiring, replace nylon cable retainers,insert backlight plug, replace main coverand connect power and communication

cable to complete installation.




Universal Communication Module (UCM) OptionalModule Layout

Side View

Top View

RS232 ActivityIndicator

RS422/485 Activity Indicator

IRBUS RS485Activity Indicator

J1-Microcontroller/Network(RS422/RS485) Port

J2-Service/Modem(RS232) Port J3-Input Power

Pin 1 Pin 1 Pin 1

Switch A0IRBUS Address

Switch A1Unused Switch (Must be set to 0)



151

Connector DescriptionTag Type Module Connector Mating Connector

J1 Microcontroller/Network(RS422/485) Port

Phoenix MSTBA2,5/8-G-5, 08

Phoenix MSTBW2,5/24-ST-5, 08

J2 Service/Modem (RS232)Port

9 Position “D” SubMiniature (Female)


J3 Input Power Phoenix MSTBA2,5/2-G-5, 08

Phoenix MSTW2,5/2-ST-5, 08

NOTES:1. UCM Weight: 410 g [0.90 lb.]

2. UCM Size: Length=136 mm [5.4 in] x Width=143 mm [5.6 in] x Depth=31 mm [1.2 in]


Connector Input and Output (I/O)

Pin J1-Microcontroller/NetworkPort

Pin J2-Service/Modem Port Pin J3-Input Power

1 IRBUS RS485 Datalink + (DL+) 1 No Connection 1 +12 To +24 VDC (VPOWER)2 IRBUS RS485 Datalink - (DL-) 2 Transmit (TX) 2 Ground (GND)3 Ground (GND) 3 Receive (RX)4 RS422/485 Transmit + (TX+) 4 No Connection5 RS422/485 Transmit - (TX-) 5 Signal Common6 RS422/485 Receive + (RX+) 6 No Connection7 RS422/485 Receive - (RX-) 7 No Connection8 Ground (GND) 8 No Connection

9 No Connection

Setting UCM SwitchesThe UCM has two sixteen position selector switches, A0 and A1.

Switch A0 is used for setting the IRBUS Address for the UCM. This switch can be in any ofthe sixteen positions. If there are multiple UCM’s on a single Base Control Module, then eachaddress for each UCM must be unique. This applies only to multiple UCM’s on a single BaseControl Module.

Switch A1 is unused at this time and must be set to zero.

UCM Port Activity LEDsThe UCM has three light emitting diodes (LEDs) to indicate the activity of the RS232,RS422/485 and the IRBUS RS485 ports. The following table indicates the different states ofthese ports.




UCM Communications ParametersThe UCM has three communication ports, RS232, RS422/485 and IRBUS RS485. Each ofthese ports has its own communication parameters that it supports.

UCM TimeoutThe UCM has three communication ports, RS232, RS422/485 and IRBUS RS485. Each ofthese ports has its own communication parameters that it supports.

RS232RS422RS485

IRBUSRS485 UCM State

off off off No power (24 VDC)on off off Boot mode, check A1 switch for being non-zero (cycle power

to exit boot mode)on on on Running, but no communication on any porton on blinking Multi-module job with inter-module communication

blinking on blinking Service Tool in useblinking on on Service Tool in use, but no response from BCM … check

connection between BCM and UCMon blinking blinking MODBUS communication in useon blinking on RS-422 port in use, but no response from BCM … check

connection between BCM and UCM or Modbus and DF1address

blinking blinking blinking All blinking together imply a continuous reboot or applicationproblem

ParameterService Tool

RS-232Modbus/DF1RS-422/485

IRBUSRS-485

Distance 50 feet (15.2 meters) 4000 feet (1218.3 Meters) 100 feet (30.4 Meters)Baud Rate 9600 300, 600, 1200, 2400,

9600, 19200, 384009600

Parity None None, Even, Odd NoneData Bits 8 8 8Stop Bits 1 1, 1.5, 2 1Configurable No Yes* No* A certified Ingersoll-Rand Service Representative will provide this configuration.



153

RS422/485 Network Wiring Diagram - Full Duplex

Tx+ Tx- Rx+ Rx- GndRS-232

DB-9

DL+ DL- GndRS-422/485RS-485

24+Power

A0 A1

Universal Communication Module (UCM)IMPORTANT: Because this is the first slave node in the Modbusnetwork, the transmit and receive lines of this node are crossed withthe transmit and receive lines of the Modbus Master. When daisy-chaining to the next slave node, do not cross the transmit andreceive lines.

Gnd

ToBCM

ToPowerSupply

Compressor Panel #1


DB-9


24+Power

A0 A1

Universal Communication Module (UCM )

Gnd

ToBCM

ToPowerSupply

Compressor Panel #2

Tx+ Tx-Rx+ Rx-

ICC-11RS-232C to RS-422Interface Converter

SW1 - DCESW2 - Simulation ModeSW3 - Position 2, Tx andRx is always on

120 VAC

RS-232DB-25

Modbus Master

FromComputer

Serial PortRS-232

Compressor Panel #3

Compressor Panel #4

Compressor Panel #5

Compressor Panel #6

Compressor Panel #nThe maximumdistance of aMODBUS Network is4000 electrical feet;i.e., the length of thewire from the RS-232to RS-422 Converter(Location A) to the lastcompressor'sUniversalCommunicationModule (Location B).

The maximum numberof devices (nodes) ona MODBUS Network is30. (For CEM forWindows and a CMConly system, themaximum is 16).

A terminating resistoris not required at theend of the network.

A

120 VAC

Modbus Address - 01(Set through software)

Modbus Address - 03IRBUS Address - any




Modbus Address - nnIRBUS Address - any

RS-4222 Twisted Pair Wireswith Ground (5 Wires)

RS-4222 TwistedPair Wireswith Ground(5 Wires)

RS-4222 TwistedPair Wires(4 Wires)

IRBUS AddressSet switch A0: 0-FSet switch A1: 0



B

NOTE: Ground wire should beconnected to one ground location only.




RS422 Network Wiring Diagram - Half Duplex


DB-9


24+Power

A0 A1

Universal Communication Module (UCM)IMPORTANT: Because this is the first slave node in the Modbusnetwork, the transmit and receive lines of this node are crossed withthe transmit and receive lines of the Modbus Master.

Gnd

ToBCM

ToPowerSupply

Compressor Panel #1

RS-232DB-9


24+Power

A0 A1

Universal Communication Module (UCM )

Gnd

ToBCM

ToPowerSupply

Compressor Panel #2

Tx+ Tx- Rx+ Rx- Gnd

Tx+ Tx-Rx+ Rx-

ICC-11RS-232C to RS-422Interface Converter

SW1 - DCESW2 - Simulation ModeSW3 - Position 1, Txenabled when RTS ON,RX enabled when RTS Off

120 VAC

RS-232DB-25

Modbus Master

FromComputer

Serial PortRS-232

Compressor Panel #3

Compressor Panel #4

Compressor Panel #5

Compressor Panel #6

Compressor Panel #nThe maximumdistance of aMODBUS Network is4000 electrical feet;i.e., the length of thewire from the RS-232to RS-422 Converter(Location A) to the lastcompressor'sUniversalCommunicationModule (Location B).

The maximum numberof devices (nodes) ona MODBUS Network is30. (For CEM forWindows and a CMConly system, themaximum is 16).

A terminating resistoris not required at theend of the network.

A

120 VAC







Modbus Address - nnIRBUS Address - any


RS-422Twisted Pair Wireswith Ground (3 Wires)

RS-422Twisted PairWires withGround (3Wires)

RS-422TwistedPair Wires(2 Wires)


B

NOTE: Ground wire should be connectedat one ground location only.



155

Terminating ResistorThe RS422/485 circuitry built into each UCM supports Alternate-Fail-safe AC Termination.This termination circuitry enhances the UCM's ability to operation in harsher (electricallynoisier) environments. Since this circuitry is built into the product, no external terminatingresistor is required. For a thorough discussion of the various termination techniques, pleaserefer to "A Comparison of Differential Termination Techniques", National SemiconductorApplication Note 903 (AN-903), August 1993. This application note can be obtained from theInternet at "www.national.com".

Typical System Layout


24 VDC

24 VDC Power

RS232

IRB

US

(RS

485)

120/240 VACPower

Base Control Module(BCM) #2

Base Control Module(BCM) #1

UniversalCommunicationsModule (UCM)

Power Supply

Operator User Interface (OUI)

24 VDC

24 VDC

IRB

US

(RS

485)

OptionalEquipment




Network Diagram

UniversalCommunicationModule (UCM)

IRBUS (RS-485) Networkfor Base Control Modulesand UniversalCommunication Modules,Twisted Pair Wires withGround (3 Wires)

To next CMC Panelor any other

Modbus compliantproduct

INGERSOLL-RANDService Tool

RS-232 toRS-422/RS-485

Converter



IRBUSAddress: 2


IRBUSAddress: 1

RS-232Cable


CMC Panel

Serial Port(COM1)

Service ToolPlug onPanel Door

RS-232Cable

Serial Port(COM1)


INGERSOLL-RANDCEM for Windows


IRBUSAddress: 6

IRBUSAddress: 5

IRBUSAddress: 4


Next CMC Panel(s) foruse in CEM for Windows



157

Technical Specification

DESCRIPTION OF STANDARD

Switches, Lights and Push ButtonsControl Power On/Off switch... activates panel power and prelube pumpCompressor trouble light (red)Emergency stop pushbutton

Microprocessor OUI240x128 pixel LCD graphic display windowTabbed folders for ease of navigationStatus Bar with compressor stateFifteen screens of compressor information and setup dataLeft/Right/Up/Down/Return push buttonsAcknowledge/Reset push buttonsStart/Stop push buttonsLoad/Unload push buttonsContrast Button

Event LogMost recent 224 events with name, time, date and valueLogged events

AlarmsTripsCommand key press (local and remote)E-Stop pressedModule control power up and downMinLoad resetAnalog input failedSetpoint change (local and remote)Automatic start and stop (when Auto Hot Start purchased)Surge UnloadCompressor StartedDriver Failed to Start

Language and Units of MeasureLanguage and Units of Measure Sets

Two Language and Units of Measure sets are select-able from the display.NOTE: The English language and psia, degF, mils are standard for all units.Spanish and kPA, degC, microns are the default alternate language unlessotherwise specified. Other Units of Measure are available upon request.

LanguagesArabic Bulgarian Chinese CroatianCzech Danish Dutch FrenchFinnish German Greek HungarianItalian Norwegian Polish PortugueseRomanian Russian Slovakian SlovenianSpanish Swedish Turkish

Units of MeasureAvailable upon request.

Control FunctionsModulate or AutodualManual Valve control for compressor setupHigh motor load limit(controls maximum opening of inlet valve)MinLoad (controls minimum opening of inlet valve)Partial Unload on Surge

Moves inlet valve to minimum load setting and bumps the bypass valve open toexit the surge condition

Minimizes duration and magnitude of pressure drop from surgeSurge Indexing

Actual/Alarm/Trip FunctionsLow oil pressureHigh/low oil temperatureHigh air temperature into last compression stageHigh stage shaft vibrations, single plane

Alarm FunctionSurge

Trip FunctionLow seal air (interlocked w/ prelube pump operation)

Display Functions (Read Only)Motor currentSystem air pressure

Copper Ground Bar

PHYSICAL DATA

Panel ConstructionNEMA 12 enclosureFormed and welded 11 gauge carbon steel cabinet, 14 gauge doorDoor gasket with butt type hingesBack panel for component mounting

DimensionsPanel1 Panel2 Controller Board

Height 54 in (137.2 cm) 54 in (137.2 cm) 12.5 in (31.8 cm)Width 32 in (81.3 cm) 35 in (88.9 cm) 18.5 in (47.0 cm)Depth 12 in (30.5 cm) 14 in (35.6 cm) 1.5 in (3.8 cm)

1 - No Starter or size 5 starter panels2 - with size 5DP or size 6 starter panels

WeightWithout starter 300 lb. (136.1 kg)With size 5 starter 350 lb. (158.8 kg)With size 6 starter 375 lb. (170.1 kg)

Component DataCanadian Standard Association (CSA)Underwriters Laboratories (UL) approved components

Control WiringHigh voltage and low voltage wiring segregationTEW wire with PVC insulation (meets NEMA VM-1 for Flame Retardance)105 degC temperature rise on insulation600 V rating, 18 gauge for instrumentation and signal, 16 gauge for controlHeat shrink wire markers for harnessClip-on wire markers internal to panelWire Ferules

Terminal Blocks300 VAC design for #22 through #10 wire sizeTubular clamp contacts and tang clamping collar, DIN Rail mounted

Push Buttons/Selector Switches/IndicatingLights

Corrosion resistant, Oil-tightDesigned and manufactured to NEMA 4/12/13Pilot lights are 120 VAC full voltage type

Control Interposing Relays300 VAC rating at 10 amp continuous60 amp make, 6 amp break at 120 VAC110/120 VAC, 50/60 Hz coil, 4 normally open poles, DIN rail mounted

ContactsNormally Open, 5 amps at 120 VAC

Pressure TransducersRanges 0-50 PSIG, 0-200 PSIG, 0-500 PSIG, 4-20 mA Output Channel1/4" NPT pressure port fitting1/2" Conduit connection head fitting for machine mounted model

Temperature Transducers0-500 degF operating range, 4-20 mA transmitter100 ohm platinum, TCR=0.00385Four compression type terminalsNEMA 4 rating

Vibration TransmittersEddy current probeVibration range 0-4 mils, Frequency range 5-3000 HzOutput Channel 4-20 mA and 100 mV/Mil, Supply voltage 18-50 VDCBarrier type screw terminals, DIN rail mountableHardened against 150 MHz and 440 MHz radio interference

Wiring HarnessOne wiring harness per deviceNEMA 4 rated




OPTIONS

Analog Inputs (Monitor, Alarm and Trip)Any TemperatureAny PressureAny VibrationAny 4-20 mA signal

Digital (Discrete) Inputs (Monitor and Alarm or Trip)Low water flowDirty inlet filter (switch supplied loose)Dirty oil filterLow oil levelHigh condensate level (common for all traps)High motor temperatureAny Discrete Input

Panel EnclosuresCooing Fan with Filter

110/115 VAC, 50/60 Hz, 0.24 Amps, 20 WattsAir flow with filter 36 CFM (61 M3/Hr)

NEMA 4 EnclosureSpace Heater, Vortex Tube Cooler

NEMA 4X EnclosureSpace Heater, Vortex Tube CoolerStainless steel or epoxy coated carbon steel

Space Heater120 VAC, 120 Watts, finned strip heaterBimetallic baseboard type thermostat set at 45 degF (7 degC)

Vortex Tube Cooler25 SCFM (42 NM3/Hr) at 100 PSIG (7 BarG) of compressed air1500 BTU/Hr (378 kCal/Hr), Thermostat set at 90 degF (32 degC)Solenoid operated valve, Air Filter

Type Z PurgeSelect-able quick and normal flow rates with metersDifferential pressure switch set at 0.2 inches (5 mm) of waterLoss of purge indication, Relief valve, Warning label

Fused Control Power DisconnectRotary handle through door, 30 amp fuse

Ground Fault Protector for UL Panels120 Vac circuits protected against ground fault currents.

Control Electrical Package (Standard on CV)Prelube Pump Motor Starter

Two horsepower and lessAvailable voltages 380, 460, 575 VACMaximum voltage rating 600 VAC, 10 Amp rating, 120 VAC coilsIEC Style

Heater ContactorIEC Style, Adjustable ambient compensated overloadsAvailable voltages 380, 460, 575 VACMaximum voltage rating 600 VAC, 10 Amp rating, 120 VAC coils

Control Power TransformerMachine tool type, 230, 460, 575 VAC to 120/95 VAC500 VA or optional 1000 and 1500 VA, 50 or 60 Hz

Transient Voltage Surge SuppressorUL 1449 ListedTested to ANSI / IEEE C62.41 category A and B environments.

Stage Data Package (Standard on CV)Interstage Air Pressure and Temperature each stage

Alarm Horn80-95 dBA, 2900 Hz

Running Unloaded Shutdown TimerTiming range and mode select-able through CMC

Water Solenoid Post Run TimerTiming range and mode select-able through CMC

Inlet Valve Tight ClosureKeeps inlet valve closed until motor reaches full speed0-30 second timer range settable by IR Service Tech

Diesel Engine Driven Compressor Control

Steam and Gas Turbine Driven Compressor Control

Main Motor Starter (Wye-Delta)NEMA Size 5 or 6Open transition type, Ambient compensated overloadsAvailable voltages 380, 460, 575 VAC, 120 VAC coils

Power Regulating Transformer120 VAC, 60 Hz, 250 VA-65% Input Channel line variation, Output Channel +5-10% NEMA

Specification±15% Input Channel line variation, Output Channel ±3%

Automatic StartingAutomatic Hot Start

REMOTE FUNCTIONS DISABLED/ENABLED Selector SwitchSolenoid Valves for IntercoolersCMC settable start up pressure setpointPost Run Water Flow Timer

Automatic Cold StartCONTROL POWER LOCAL/OFF/ COLD Selector SwitchStrobe LightSolenoid Valves for Intercoolers and Instrument Air LineCMC settable start up pressure setpointPost Run Water Flow TimerStart TimerLube Oil Alarm Bypass Timer

COMMUNICATIONS OPTIONS

Communications Card(s)Up to three cards per module RS-422/485Local/Network Selector Switch

Direct CMC Communication with RS422/RS-485Requires programming application by customerUtilizes standard MODBUS protocol or Allen-Bradley DF1 protocol for

PLC2, PLC5 and SLC500 devices

Hard Wired CommunicationREMOTE FUNCTIONS DISABLED/ENABLED Selector SwitchContacts for Remote Start/Stop, Load/Unload, Acknowledge/ResetTrouble Indication Contacts (Alarm and Trip, Alarm Only or Trip Only)Remote 4-20 for Pressure SetpointRunning Unloaded Contact

Centac Energy Master (CEM)Features

Sequencing, load sharing and data logging for eight (8) compressorsA CMC Communication Adapter mounted in each CMC panelMax distance from last compressor to CMC Communication Adapter is

4000 feet (1218 meters)RS-232 to RS-422 Converter

CEM Personal ComputerIntel Pentium processor, 32 MBytes RAM, CD ROM Drive, 3.5 inch

diskette drive, Program size approximately 30 MByte; however, hard diskshould be sized for data logging (recommend 100 MBytes), Windows 95or NT (NT Preferred), Color monitor, Printer (Optional)

CUSTOMER RESPONSIBILITIESThree phase powerClean, dry control air 80-150 PSIG (5.62-10.55 kg/cm2)

Control air tubing from control air header, 1/4 in (0.635 cm) FNPTconnection

Mount and wire external switches and field wired devicesTuning control parameters for systemCurrent transformer – instrument grade

0-5 ampBetter than 1% accuracy

CONTROLLER OPERATING ENVIRONMENT

Electrical Operation115 VAC ±5%24 VDC Instruments except three wire RTDs32 VA of AC power requirement50/60 Hz AC supply frequency

TemperaturesOperating temperature 32 to 140 degF (0 to 60 degC)Storage temperature -4 to 158 degF (-20 to 70 degC)

Relative Humidity95% (maximum) non-condensing

DOCUMENTATIONInstruction bookElectrical schematicPanel Outline drawing (Optional)



1

GlossaryThe following glossary is generic; therefore,some terms do not apply to all CMC systems.

AB — See Allen-Bradley.Absolute Address — For Modbus compliant devices, thespecific memory location for a coil, discrete input, register oranalog input. The address is a five-digit number.Accelerometer — An instrument used to measureacceleration. These instruments are typically used for bearinganalysis.Actuator — The device on a control valve that provides thepower to move the valve to a position. Typically, this power issupplied through control air to open (for the inlet valve) andclose (for the bypass valve). For “fail-safe” operation, aspring is used to drive the valve in the opposite direction.Address — This term is used by PLC manufacturers toindicate a specific memory location within the unit. Theselocations typically reference the value for data items likeanalog inputs, analog outputs, digital inputs, digital outputs,coils and intermediate computational states. Through thesememory locations, the current system pressure, first stagevibration and discharge air temperature can be determined.Alarm — The term used to indicate that an abnormal conditionexists that should be addressed by an operator. Thiscondition has not reached a level that would shut down thecompressor.Alert — See Alarm.Allen-Bradley — A manufacturer of control products, mostnotably PLCs. These PLCs are used for various industrialapplications including controlling compressors.American Wire Gage (AWG) — The measurement systemused to indicate the diameter of the wire. The gage numberincreases as the wire diameter decreases.Analog Input — An electrical device, which represents aspecific real world pressure, temperature, vibration orcurrent. As these items fluctuate, the electrical signal to andfrom the microprocessor board also fluctuates proportionallyto the amount of change. The electrical signal is typically in theform of a current that ranges from 4 to 20 milli-amps inmagnitude.Analog Output — An electrical signal, which typicallyrepresents the inlet and bypass valve position. As thesevalves fluctuate, the electrical signal to and from themicroprocessor board also fluctuates proportionally to theamount of change. The electrical signal is typically in the formof a current that ranges from 4 to 20 milli-amps in magnitude.Auto-Cold Start — A control mode that automaticallyenergizes the panel power, opens cooling water flow valveto the coolers, turns on seal air, starts and loads thecompressor on a low pressure condition.

Auto-Dual — The control mode that automatically unloadsa modulating compressor when the bypass valve positionreaches a specified value or the check valve closes. Onceunloaded, this control mode will automatically reload thecompressor when the system pressure drops below aspecified value.Auto-Dual Unload Timer The time delay, in seconds,at which the machine will be unloaded after the bypassvalve has passed and stayed below the unload point whenAutodual is active.Auto-Hot Start — A control mode that automatically startsand loads the compressor on a low-pressure condition.Auto-Reload — The portion of Auto-Dual control mode thatautomatically reloads the compressor when the pressuredrops below a specified value.Auto-Start Pressure The system pressure, inpressure setpoint units, at which the machine will startwhen either auto hot or cold start is active.Axial Position — The position of the rotating assemblywith respect to the horizontal axis of the pinion.

Baud Rate — Unit of signaling speed for datacommunications. The speed in baud is the number of linechanges (in frequency, amplitude, etc.) or events persecond. At low speeds each event represents only one bitand baud rate equals bits per second. As speed increases,each event represents more than one bit, and baud ratedoes not truly equal bits per second.BCM — Base Control Module. The device of the CMC thatreceives all of the compressor inputs and outputs andmakes decisions about how the compressor is to operate.Binary Signal — The type of signal used incommunications. Binary refers to the smallest size of databeing transmitted, a bit.Blow-off Valve — Also know as a bypass valve or anti-surge valve. This valve protects the compressor fromsurge by bypassing a percentage of the compressed air tothe atmosphere, which results in keeping the compressorloaded above the surge point.BPS — Bits per second. Unit of signaling speed for datacommunications.Bypass Valve — See blow-off valve.

CE Mark — The CE Mark is a combination of variousindividual European standards into one set of standards forthe entire European community. The Mark is a selfdeclaration and self marking process. Once you haveproven that the particular equipment meets therequirements of CE Mark and have the data to back it up,you may mark the product with the CE Mark.Citect — One of many SCADA software packages thatcan be used for air system integration.




Choke — Also know as stonewall. This is the maximum flowthat can be compressed by a given machine’s hardwareconfiguration.Circuit Breaker — An automatic switch that stops the flowof electric current in a suddenly overloaded or abnormallystressed electric circuit.CMC — Centac MicroController.CMC System — Any combination of CMC controlcomponents which when combined create a control system.The typical CMC system consists of a Base Control Module(BCM), Operator User Interface (OUI), and Power Supply(PS). A common variation on the typical system is the additionof a Universal Communications Module (UCM).Coast Timer — The time interval, in seconds, between acompressor stop or trip and the motor coming to a completestop. The timer is used to inhibit restarting.Compressor Load, Load — The power consumption of thecompressor. It is typically indicated in amps, kilowatts, SCFM,etc.COM Port — See Serial Port.Control Transformer — The transformer that is used toreduce the incoming voltage (for the prelube pump motor andoil heater) to approximately 120 volts for controlling the CMCelectrical devices (relays, power supply, etc.).Control Valve — The inlet or bypass valve used to controlpressure or current.Control Variable, Process Variable — The variable beingregulated. When at MinLoad the control variable is load for theinlet valve and System Pressure for the bypass valve. Whenat MaxLoad the control variable is load and when loaded thecontrol variable is System Pressure.CSA Approval — Canadian Standards Association approvalis required for all electrical devices shipped into Canada. Thisassociation is similar to UL for the United States and CE forEurope.CT — Current Transformer.CT Input Channel — The current transformer input channel.CT Ratio — Current Transformer Ratio. The currenttransformer ratio used in displaying the motor current; e.g.600:5 = 120.Current Transformer — The electrical device used tomeasure the amps of the main drive motor. For our standardapplication, we only measure the current from one of thethree phases.

Daisy Chain — A method of wiring a communicationnetwork. This method starts with the “master” and it is wireddirectly to compressor #1. Compressor #2 is wired tocompressor #1, then compressor #3 is wired to compressor#2.Data Highway Plus — A communication protocol used byAllen-Bradley PLC 5 and SLC500 PLCs.DCS — See Distributed Control System.degC — Degrees Celsius, Centigrade.

degF — Degrees Fahrenheit.DH+ — See Data Highway Plus.Derivative Mode — Provides a change in the controlvariable (through the inlet or bypass valve) based on therate of change of the error (setpoint pressure minussystem pressure).Derivative Constant — Also know as the rate time, inunits of seconds.Design Point — The pressure and capacity required atmaximum ambient conditions.Digital Device — A device which is either on or off; e.g.,the N.C. contact on the seal air switch.Discrete Device — See Digital Device.Discharge Pressure — The gas pressure between thelast stage of compression and the check valve.Distributed Control System — A system that attemptsto control an entire plant or process with multipleindependent local controllers by networking these localcontrollers to a central computer through digitalcommunications. These central computers can be a PC,PLCs or other larger systems. Some manufacturers ofthese DCS products are Bailey, Honeywell, Allen-Bradley,Siemens, and others.Drain Wire — An insulated wire in contact with a shieldthroughout its length, and used for terminating the shield.Dry Contacts — A set of contacts that require a powersource supplied by others (customer). This is the normaltype of contacts that we provide.

Electro-pneumatic — A term used to indicate acombination of electronics and pneumatics. In the past, weprovided electro-pneumatic panels as standard equipment.With the advent of digital computers, most all control panelsare electronic.ERAM — Erasable Random Access Memory.

FactoryLink — One of many SCADA software packagesthat can be used for air system integration.FLA — Motor Full Load Amps. The motor amperage at fullload, this value is found on the motor nameplate.Flexible Conduit — Small diameter hose, made of plasticcoated aluminum, which is used to enclose wire from thecontrol panel to machine mounted instruments.Fused Disconnect — As a safety precaution, this optionremoves power from the panel before the door is opened.By turning the rotary door handle, the panel power isterminated. The disconnect would have to be mountedexternal to the panel enclosure. The short circuit capacity,maximum ground fault, motor full load amps, motor lockedrotor amps and motor voltage must be known to size thedisconnect properly.

Ground — A connection to earth or to some extendedconducting body that serves instead of the earth.



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Ground Loop — An unwanted, continuous ground currentflowing back and forth between two devices that are atdifferent ground potentials.Grounded System — An electrical system in which at leastone point (usually a wire) is intentionally grounded.

High Load Limit — See HLLHLL — High Load Limit. The load that the controller maintainswhen at MaxLoad.

I/O — See Input/Output.IBV — Inlet Butterfly Valve. See Inlet Valve.IEC — International ElectroTechnical Commission is thegoverning body of Europe for electrical equipment and codes.IGV — Inlet Guide Vanes. See Inlet Valve.Inlet Unload Position — The position of the inlet valve whenin the unloaded state.Inlet Valve — The device used on the inlet pipe to thecompressor that restricts the amount of airflow to thecompressor. This valve can be a butterfly valve or a valvewith inlet guide vanes.Input/Output —The hardware interface between thecompressor and the control system. This term genericallyapplies to the entire interface circuit including sensor, wiring,and junction points.Instrument Air — The air supply to the panel that is directedto the power air system for the inlet and bypass valves andthe compressor seals.Integral Mode — Provides a change in the control variable(through the inlet or bypass valve) based on the time historyof the error (setpoint pressure minus system pressure).Integral Time Constant—This value is expressed inrepeats per second and represents the number of times persecond the integral mode acts.Intellution — One of many SCADA software packages thatcan be used for air system integration.Interface — The hardware or software device used tocommunicate between products.Interlock — An electrical function that prevents thecompressor from starting in the event that the function hasnot been satisfied. For example, the seal air interlock preventsthe compressor from starting until the seal air pressure isadequate.IRBUS — The proprietary communication protocol used tocommunicate to and from one or many Base Control Modules(BCM), Universal Communication Modules (UCM) and OperatorUser Interfaces (OUI).

Loopback — A diagnostic test in which a transmittedcommunication signal is returned to the sending device afterpassing through all or part of the communication network. Thistest compares the transmitted signal to the received signal.The test passes if the signals are identical.

MA, mA — MilliampereMaintained Contact — A contact closure that remainsclosed.MaxLoad — The message displayed on the OUI Status Barwhen the machine is running at MaxLoad.MinLoad — The message displayed on the OUI Status Barwhen the machine is running at MinLoad.MMI — Man Machine Interface. The term used to indicatethe device or method used for a human to interface with amachine. Typically these interfaces are LCD displays orcomputer screens. For the CMC, the MMI is the OperatorUser Interface (OUI).Modbus — A sixteen-bit communication protocol originallydeveloped for Modicon PLCs. This protocol has become adefacto standard for industrial equipment.Modicon — A PLC brand name manufactured bySchneider Automation.Modulate — The control mode that opens and closes(modulates) the inlet or bypass valve to maintain a constantdischarge pressure. This is the primary control mode forcentrifugal compressors.Momentary Contact — A contact closure that closes andthen opens.

N.C. — Normally Closed. Used to indicate the state of acontact when no power is applied.N.O. — Normally Open. Used to indicate the state of acontact when no power is applied.Natural Curve — The set of pressure and capacity pointsthat define the operating characteristic of the centrifugalcompressor.Natural Surge — The point on the natural curve that isrepresented by the maximum pressure and minimumcapacity.NEMA — National Electrical Manufacturers Association.Network — A series of points, nodes or devicesconnected by some type of communication medium.

On-Line/Off-Line — Control mode that allows the systemdischarge pressure to fluctuate between two pressuresetpoints. The compressor will load when the actualpressure is below the lower setpoint pressure and willunload when it reaches the higher setpoint pressure. Thistype of control mode is normally used on reciprocating androtary compressors.OUI — Operator User Interface. The device on the CMC thatgathers user inputs and provides compressor operatingstatus.

Parity — The addition of non-information bits to make up adata transmission block that ensures the total number of 1sis either even (even parity) or odd (odd parity). This is usedto detect errors in communication transmission.Partial Unload — See Surge Absorber.




Password — The four digit parameter used to determinewhen the user can modify setpoints. The range of thispassword is 0000 to 9999.PID — Proportional, Integral, Derivative. The parameters usedto adjust the behavior of PID control loops.PLC — Programmable Logic Controller. This hardwaredevice is configurable such that many types of analog anddigital inputs and outputs can be utilized to control variousindustrial products.PLC 5 — Type of Allen-Bradley PLC used for largeapplications.Pneumatic — Run by or using compressed air.Positioner — The device on a control valve that instructs theactuator how much (to what position) to move the valve.PROM — Programmable Read Only Memory.Proportional Mode — Provides a change in the controlvariable (through the inlet or bypass valve) proportional to theerror (setpoint pressure minus system pressure).Proportional Band Constant — The percent change insystem air pressure that causes a percent change in thevalve position. This value is dimensionless.Protocol — A formal set of conventions governing theformatting and relative timing of message exchange betweentwo communication systems.

RAM — Random Access Memory.Relative Address — For Modbus compliant devices, thefour-digit address within the range of 0-9999. The relativeaddress can be determined from the absolute address bydeleting the type (the ten-thousandth place) and subtractingone.Reload Percent — The reload pressure, in percent of userpressure set point, at which the machine will load whenAutodual is active.Rigid Conduit — Small diameter pipe, made of carbon steelwith welded connections, which is used to enclose wire fromthe control panel to machine mounted instruments. Thisconduit is typically used in hazardous area classifications.Rise To Surge — The amount of pressure from theoperating pressure to the natural surge pressure. This amountis usually expressed in percent.RS-232 — Electronic Industries Association interfacestandard between data terminal equipment and datacommunication equipment, using serial binary datainterchange. This is the most common standard used byindustry.RS-232 to RS-422/485 Converter — A hardware devicethat electrically converts an RS-232 signal into an RS-422 orRS-485 signal.RS-422 — Electronic Industries Association interfacestandard that specifies electrical characteristics for balancedcircuits and extends transmission speed and distancesbeyond RS-232. This standard is a balanced voltage systemwith a high level of noise immunity.

RS-485 — Electronic Industries Association balancedinterface standard similar to RS-422, but uses a tri-statedriver for multi-drop applications.RTD — Resistance Temperature Detector. An instrumentthat measures temperature by detecting the voltage acrossthe RTD material (mostly platinum). The temperature isdetermined because as the temperature increases theresistance increases.RTU — Remote Terminal Unit. A device typically used fordata acquisition to gather data. By using this definition, theBase Control Module is an RTU.

SCADA — Supervisor Control and Data Acquisition. Thegeneric classification for software that gathers data forcontrol of industrial products.Sequencer — A hardware or software device thatcontrols the order in which compressors starts, stops,loads and unloads. Some sequencers also control loadingand unloading through incremental pressure setpointsamong the compressors. For example, in a three-compressor application the setpoints may be 101 psi forcompressor #1, 100 psi for compressor #2 and 99 psi forcompressor #3. Assuming the pressure transducers werecalibrated within one psi of each other and the machineswere running unloaded, this configuration would drivecompressor #1 to load first when the pressure dropped to101 psi.Serial Device — A Personal Computer (PC), ProgrammableLogic Controller (PLC), Distributed Control System (DCS) orany other device that can transmit, receive and interpret anRS422/485 formatted signal.Serial Port — The RS-232 connection on the back of a PCto communicate with other equipment. This connection istypically referred to as COM1. A single PC can have morethan one serial port.Service Tool — The software used on the PC toconfigure, tune, record and log data from the CMC.Setpoint Ramp Rate — The gradual increase of thesystem pressure set point during a loading operation of thecompressor. The ramping of the system pressure set pointhelps to smooth the transition and prevents a pressureovershoot in the air system upon initial compressor loading.Shielded Wire — Wire that has a sheet, screen or braidof metal, usually copper, aluminum, or other conductingmaterial placed around or between electric circuits orcables or their components, to contain any unwantedradiation, or to keep out any unwanted interference.SLC500 — Type of Allen-Bradley PLC used for relativelysmall applications and is lower in cost than an equivalentPLC 5.Start Timer — The time interval, in seconds, betweenpressing the Start button and the compressor is running atfull speed. The timer is used to transition wye delta



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starters, inhibit loading, de-energize the prelube pump, anddisable the alternate alarm and trip setpoints.Status Bar — The Status Bar provides four distinct types ofinformation (Compressor Operating State, Compressor Status,Compressor Control Location and Page Number). This regionis always visible from any folder and page combination.Stonewall — See Choke.Surge Absorber — The reaction of the control system to asurge that pops the bypass valve open by a small percentageto get the compressor out of the surge condition. This featureis initiated by surge detection.Surge Anticipation — The ability of a control system toprevent surge by predicting that a surge is about to happen.Surge Detection — The ability of a control system toindicate that a surge has happened. This feature is importantbecause a persistent surge condition can damage thecompressor. Once detected, the control system can respondto the event by taking a corrective action; i.e., by opening thebypass valve.Surge Indexing — A method of automatically increasing thesetting of TL upon a surge.Surge Indexing TL — The setpoint at which the inlet valvecontrols to MinLoad.Surge Line — A series of points that represent naturalsurge for various inlet pressure conditions.Surge PTX — Surge Pressure Transducer. Surge PTX ismounted between the last compression stage and the checkvalve.Surge Sensitivity — A setpoint that is used to indicate themagnitude of pressure and current changes that occur duringa surge condition. This setpoint determines when the controlsystem detects a surge.Surge Unload — The reaction of the control system to asurge that unloads the compressor to exit the surge condition.This feature is initiated by surge detection.System Pressure — The pressure at the location of thesystem pressure transducer.

Terminal Block — A device that is used to connect towires. Typically, these blocks are provided for customer fieldwiring to the panel and when one wire is to be connected tomultiple devices.Terminating Resistor — A resistor placed at the end of acommunication network for absorbing or sufficientlyattenuating signals incident on it so that they are not reflectedback into the transmission line at amplitudes where theywould cause distortion of the data signal. Typically, a resistoris placed at each end of the network to help eliminate noise.Thermocouple — A device used to measure temperaturesaccurately and consists of two dissimilar metals joined so thata voltage is generated between to the contacts of the twometals as the temperature changes.Throttle Limit — See TL.

Throttled Surge — The condition created by closing theinlet valve past the surge point to maintain constantpressure.Tight Closure — A term used to describe the inlet valveposition when the compressor is not running and starting.The inlet valve ideally is closed tightly when stopped toprevent reverse rotation of the compressor if the checkvalve fails. Also, to reduce the load on the compressorduring starting, the inlet valve can be held closed for ashort period of time (less than thirty seconds) after thestart button is pushed. This is most typically done oncompressors at high altitude, most notably snow makingapplications. Bearing analysis must be done prior to usingthis option.TL — Throttle Limit. Establishes the minimum flow throughthe machine when loaded, it is the maximum point of inletvalve throttling. If system demand is below this throttlepoint, the compressor must bypass air to maintain pressuresetpoint or unload.TL increment value — When Surge Indexing is enabled,the TL increment value is the amount added to the SurgeIndexing TL upon a surge. The Surge Indexing TL will stopbeing incremented when and if the value reachesMaxLoad.Transducer — An electrical device that provides a usableoutput (4-20 mA, 0-5 vDC, etc.) in response to a measuredproperty (pressure, temperature, etc.).Transformer — An electrical device that transfersenergy from one circuit to another by electromagneticinduction.Transient Voltage Surge Suppressor — An electricaldevice that prevents temporary over-voltages of shortduration (typically associated with lightning strikes andground faults on an ungrounded system) from damagingother electrical equipment.Transmitter — An electrical device that sends the digitalrepresentation of a real measured value (e.g., pressure,temperature), to the BCM in the control panel for analysisand display.Turndown — The amount of capacity that can bedecreased from full load (maximum load) at a constantpressure before the bypass valve begins to open to avoidsurge. This amount is usually expressed as a percent offull load capacity.TVSS — See Transient Voltage Surge Suppressor.Twisted Pair Wire — Paired cables allow balanced signaltransmission, which results in signals with low noise. Dueto the improved noise immunity of twisted pairs, dataspeeds are usually higher than those of multi-conductorcables.

UCM — Universal Communications Module. The device thatallows outside systems to communicate with the CMC.UL — Underwriter’s Laboratory.




Ungrounded System — An electrical system, without anintentional connection to ground.Unload — The operating mode that passes a small amount ofair through the compressor and bypasses it to theatmosphere. In this mode, the inlet valve is cracked open asmall amount and the bypass valve is fully open. This mode isused when starting the compressor before loading, stoppingthe compressor and during periods of no demand.Unload Point — The bypass valve position, in percent open,at which the Autodual unload timer will start timing to unloadthe compressor when Autodual is active.User Pressure Set Point — The local control pressure setpoint.

Valve Stroking — The process of calibrating the valves toalign the fully open position to 100 percent and the fully closedposition to 0 percent of output signal.VDC — Volts Direct CurrentVoltage Regulator — An electrical device that maintainsvoltage to a predefined level.

Wait Timer — The delay interval, in seconds, betweenpower up and the ready state.Wire Gage — See American Wire Gage.Wonderware — One of many SCADA software packagesthat can be used for air system integration.

Z-Purge — Required when the customer environment isDivision 2. A Type Z Purge reduces the classification withinan enclosure from Division 2 too non-hazardous. Whenprovided, a NEMA 4 or NEMA 4X enclosure is required. Handvalve selectable quick and slow purges, with flow meters areprovided to regulate the amount of gas entering the panel. Adifferential pressure switch is wired to a light on the front ofthe panel to indicate if there is a loss of purge gas. A reliefvalve is installed to prevent over-pressurization and awarning label, text below, is affixed to the front of the panel.



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Service Tool VariableNamesThe following variable names are used in theCMC Service Tool.

Ad_unload_tmr — Autodual unload timer. The time delay, inseconds, at which the machine will be unloaded after thebypass valve has passed and stayed below the unload pointwhen Autodual is active.ASF — Adjusted Service Factor. The Ingersoll-Rand suppliedvalue for determining MaxLoad.Auto_Start_Pressure — The system pressure, in pressuresetpoint units, at which the machine will start when eitherauto hot or cold start is active.

Bat_Var_1 — Battery Backed Variable 1. Passwordcharacter 1 that is entered by the user to enable set pointchanges. This value is compared to the system passwordcharacter 1.Bat_Var_2 — Battery Backed Variable 2. Passwordcharacter 1 that is entered by the user to enable set pointchanges. This value is compared to the system passwordcharacter 2.Bat_Var_3 — Battery Backed Variable 3. Passwordcharacter 1 that is entered by the user to enable set pointchanges. This value is compared to the system passwordcharacter 3.Bat_Var_4 — Battery Backed Variable 4. Passwordcharacter 1 that is entered by the user to enable set pointchanges. This value is compared to the system passwordcharacter 4.Bat_Var_5 — Battery Backed Variable 5. The power on hourmeter.Bat_Var_6 — Battery Backed Variable 6. The running hourshour meter.Bat_Var_7 — Battery Backed Variable 7. The loaded hourmeter.Bat_Var_8 — Battery Backed Variable 8. The number ofstarts counter.Bv_Closed_Value — Bypass Valve Closed Value. Thissetting determines the value at which the bypass valve isconsidered closed. This value is used in logic to determinewhen to release the inlet valve from MinLoad control andenable the inlet valve for pressure control etc.Bv_Open_Value — Bypass Valve Open Value. This settingdetermines the value at which the bypass valve is consideredopen. This value is used in logic to determine when to releasethe inlet valve for unloading.BV_P_PID_D — Bypass Valve Pressure PID Derivative. TheBypass valve pressure control derivative constant,dimensionless.

BV_P_PID_I — Bypass Valve Pressure PID Integral. TheBypass valve pressure control integral constant,dimensionless.BV_P_PID_P — Bypass Valve Pressure PID Proportional.The Bypass valve pressure control proportional constant,dimensionless.BV_Unload_Rate — Bypass Valve Unload Rate. Thissetting determines the rate at which the bypass valve willopen during an unload sequence.Bypass_Valve_C — Bypass Valve Command. Theposition, in percent open, sent to the bypass valve by thecontroller. This is the value of an analog output.Bypass_Valve_Manl — Bypass Valve Manual. Themanual bypass valve position, in percent open.

Coast_Timer — The time interval, in seconds, between acompressor stop or trip and the motor coming to a completestop. The timer is used to inhibit restarting.CT_Ratio — Current Transformer Ratio. The currenttransformer ratio used in displaying the motor current; e.g.600:5 = 120.Current_Rate_SP — The current rate set point for theanalog surge sensor.

HLL — High Load Limit. The load that the controllermaintains when at MaxLoad.

Inlet_Valve_C — Inlet Valve Command. The position, inpercent open, sent to the inlet valve by the controller. Thisis the value of an analog output.Inlet_Valve_Manl — Inlet Valve Manual. The manual inletvalve position, in percent open.IV_HLL_PID_D — Inlet Valve High Load Limit PID Derivative.The inlet valve MaxLoad control derivative constant,dimensionless.IV_HLL_PID_I — Inlet Valve High Load Limit PID Integral.The inlet valve MaxLoad control integral constant,dimensionless.IV_HLL_PID_P — Inlet Valve High Load Limit PIDProportional. The inlet valve MaxLoad control proportionalconstant, dimensionless.IV_P_PID_D — Inlet Valve Pressure PID Derivative. Theinlet valve pressure control derivative constant,dimensionless.IV_P_PID_I — Inlet Valve Pressure PID Integral. The inletvalve pressure control integral constant, dimensionless.IV_P_PID_P — Inlet Valve Pressure PID Proportional. Theinlet valve pressure control proportional constant,dimensionless.IV_TL_PID_D — Inlet Valve Throttle Limit PID Derivative.The inlet valve MinLoad control derivative constant,dimensionless.IV_TL_PID_I — Inlet Valve Throttle Limit PID Integral. Theinlet valve MinLoad control integral constant, dimensionless.




IV_TL_PID_P — Inlet Valve Throttle Limit PID Proportional. Theinlet valve MinLoad control proportional constant,dimensionless.IV_Unld_Pos — Inlet Valve Unload Position. Inlet valveposition when the compressor is running unloaded.IV_Unload_Rate — Inlet Valve Unload Rate. This settingdetermines the rate at which the inlet valve will open duringan unload sequence.

M_rate_current — The steady state current rate value.M_rate_pressure — The steady state pressure rate value.Manual_C — Manual Control. (1) Enables and (0) disablesmanual valve control.MaxLoad — The message displayed on the OUI Status Barwhen the machine is running at MaxLoad.MinLoad — The message displayed on the OUI Status Barwhen the machine is running at MinLoad.Motor_Current — Motor current, in amps.

Oil_Pressure — Oil pressure.Oil_Pressure_LAV — Oil Pressure Low Alarm Value.Oil_Pressure_LAV2 — Oil Pressure Low Alarm Valueduring running, coasting or stopped.Oil_Pressure_LTV — Oil Pressure Low Trip Value.Oil_Pressure_LTV2 — Oil Pressure Low Trip Value duringrunning, coasting or stopped.Oil_Temp_HAV — Oil Temperature High Alarm Value.Oil_Temp_HAV2 — Oil Temperature High Alarm Value duringrunning, coasting or stopped.Oil_Temp_HTV — Oil Temperature High Trip Value.Oil_Temp_HTV2 — Oil Temperature High Trip Value duringrunning, coasting or stopped.Oil_Temp_LAV — Oil Temperature Low Alarm Value.Oil_Temp_LAV2 — Oil Temperature Low Alarm Value duringrunning, coasting or stopped.Oil_Temp_LTV — Oil Temperature Low Trip Value.Oil_Temp_LTV2 — Oil Temperature Low Trip Value duringrunning, coasting or stopped.Oil_Temperature — Oil temperature.

PASSWD1 — Password Variable 1. This is the systempassword character 1.PASSWD2 — Password Variable 2. This is the systempassword character 2.PASSWD3 — Password Variable 3. This is the systempassword character 3.PASSWD4 — Password Variable 4. This is the systempassword character 4.Pressure_Rate_SP — The pressure rate set point for theanalog surge sensor.PSP_Ramp — Pressure Set Point Ramp Rate. The rate atwhich the system pressure set point is incremented to theuser system pressure set point. This is used to preventsystem pressure overshoot when loading the compressor.

PSP_Tol — Pressure Setpoint Tolerance. This settingdetermines the pressure value tolerance at which valvecontrol transitions between states; i.e., load limit topressure control.

Reload_Percent — The reload pressure, in percent ofuser system pressure set point, at which the machine willload when Autodual is active.

Stage(n)_Temp — Stage (n) Temperature. This airtemperature for stage “n”, where “n” can be 1, 2, 3, 4 or 5,is measured at the discharge from the inter or after cooler.This is the value of an analog input.Stage(n)_Temp_HAV — Stage (n) Temperature HighAlarm Value. This is an air temperature set point for thehigh alarm value. This applies to stage “n”, where “n” canbe 1, 2, 3, 4 or 5.Stage(n)_Temp_HAV2 — Stage (n) Temperature HighAlarm Value during running, coasting or stopped.. This is anair temperature set point for the high alarm value of the 2xmultiplier. This applies to stage “n”, where “n” can be 1, 2,3, 4 or 5.Stage(n)_Temp_HTV — Stage (n) Temperature High TripValue. This is an air temperature set point for the high tripvalue. This applies to stage “n”, where “n” can be 1, 2, 3, 4or 5.Stage(n)_Temp_HTV2 — Stage (n) Temperature HighTrip Value during running, coasting or stopped.. This is anair temperature set point for the high trip value of the 2xmultiplier. This applies to stage “n”, where “n” can be 1, 2,3, 4 or 5.Stage(n)_Vib — Stage (n) Vibration. This vibration forstage “n”, where “n” can be 1, 2, 3, 4 or 5. This is the valueof an analog input.Stage(n)_Vib_HAV — Stage (n) Vibration High AlarmValue. This is a vibration set point for the high alarm value.This applies to stage “n”, where “n” can be 1, 2, 3, 4 or 5.Stage(n)_Vib_HAV2 — Stage (n) Vibration High AlarmValue during running, coasting or stopped. This is avibration set point for the high alarm value of the 2xmultiplier. This applies to stage “n”, where “n” can be 1, 2,3, 4 or 5.Stage(n)_Vib_HTV — Stage (n) Vibration High Trip Value.This is a vibration set point for the high trip value. Thisapplies to stage “n”, where “n” can be 1, 2, 3, 4 or 5.Stage(n)_Vib_HTV2 — Stage (n) Vibration High Trip Valueduring running, coasting or stopped.. This is a vibration setpoint for the high trip value of the 2x multiplier. This appliesto stage “n”, where “n” can be 1, 2, 3, 4 or 5.Start_Timer — The time interval, in seconds, betweenpressing the Start button and the compressor is running atfull speed. The timer is used to transition wye deltastarters, inhibit loading, de-energize the prelube pump, anddisable the alternate alarm and trip setpoints.



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Surge_PTX — Surge Pressure Transducer. Surge_PTX ismounted between the last compression stage and the checkvalve.

TL — Throttle Limit. Establishes the minimum flow through themachine when loaded, it is the maximum point of inlet valvethrottling. If system demand is below this throttle point, thecompressor must bypass air to maintain pressure setpoint orunload.TL_Tol — Throttle Limit Tolerance. This setting determines theload value tolerance at which inlet valve control transitionsfrom pressure control to MinLoad control.

Unload_Point — The bypass valve position, in percent open,at which the Autodual unload timer will start timing to unloadthe compressor when Autodual is active.User_PSP — User Pressure Set Point. The local controlpressure set point.

Wait_Timer — The delay interval, in seconds, betweenpower up and the ready state.

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